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After recently swapping out my alternator, my truck lights are slightly dimming repeatedly. It's especially noticeable when I turn on the dome lights. Is it a grounding issue? The alternator doesn't physically touch the metallic base at all, but seems to be grounded only via the two bolts that hold it up and in it's right place. Should I take it off and sand any metal that connects from the bolts to the alternator?

I was having electrical issues on my 2005 GMC Sierra 1500, which is at 197,000 miles. The issues were things like pulsing lights (interior and exterior and low voltage fluctuation (14.0v to 11.8v) so I replaced the alternator with a premium 160amp remanufactured one from CarQuest. Now my voltage seems high, sitting at 14.9v-15.2v during idle. The pulsing went away, but now it pulses when I rev the engine. I will leave it at about 1500 RPMs and it will steadily pulse until I release the gas. Is this an issue with the alternator or something else?

I'm not sure how far ill get with this but here goes. I have a 2018 GMC Sierra 1500 5.3L C engine code non flex. Its got 20k on it when i bought it had a crappy napa battery in it but the adaptive charging system worked fine with the napa battery it would be a 14.4 volts on start up and then drop down to 12 as it should and the back up to 14 per the conditions listed in the service info well i replaced the 94r napa battery with a 94r oriellys agm battery and the voltage would inky stay at 14.4 not drop down to 12 when electrical loads are low so i hooked up the scan tool at my shop and see that according to the BCM the battery was at 67%charged (all other data was normal and in the right conditions for the charging sytem to drop down to 12 volts) but the state of charge has to be at least 80% so i tried charging the battery and state of charge on the scan tool never changed so i attributed it to the fact that i put an agm battery in the truck and the BCM didnt like this so i went and exchanged it for a non agm 94r battery and intalled it well after driving it for a bit the charging system still did not drop down to 12 volts despite low electrical load. Ill hook the scan tool back up tomorrow and see what the BCM thinks the state of charge is but has anyone else encountered this? Thanks.

I've read threads on here, read other threads (from other sites), spoke with people etc. MY MAIN GOAL OF THIS POST IS TO SEE IF ANYONE HAS ANY COMMENTS OR SUGGESTIONS ON MY WIRE DIAGRAM BEFORE I PULL MY TRUCK APART. THANK YOU My goal is to add the following: 1. High Output Alternator (320A Iraggi) 2. Add Second Battery (Optima Yellow Group Size D34-78) 3. Upgrade All Charging wires to 1/0 Gauge (GP car Audio Power Wire w/Big 3 kit) From what I gather, The route that i'm going to take is as follows: 1. Install the Alternator 2. Run 1/0 Gauge Ground from (-) of Alternator to Frame (Leave factory wire connected) and to (-) of Factory Battery 3. Run 1/0 Gauge Power from (+) of Alternator to (+) of Factory Battery (fused @ 320A) 4. Run 1/0 Gauge Power from (-) of Factory Battery to (-) of Second Battery and to Body Ground 5. Run 1/0 Gauge Power from (+) of Factory Battery (fused @ 320A) to (+) of Second Battery (fused @ 320A) 6. From there all Power needed for AUX Equipment (Amps, Rock Lights, Inverters, etc) will Run from the (+) of the Second Battery (Fused appropriately) I did a lot of research into this and the only things that had any second thoughts on were if I should run a relay or not and if i should run the 1/0 gauge wire through the current sensor. (not sure if it would even fit). I decided not to do either. The first of which I chose not to do, mainly for the fact that the relay has a voltage drop of its own (minor), but also, it's removal has been the fix for many people in car audio to reduce lights from flickering. The amount of battery capacity that I have won't have issues with me needing to isolate my batteries. The second of which I chose not to do, was only because I read a lot of posts (mainly in car audio forums) that didn't do this and had no issues. I feel that the current wire that is running through the sensor must suffice. I'm still a bit on the fence on this one. But, I could only find maybe 1 or 2 instances where people did this modification and it was for much smaller rated systems. Neither seemed to have any problems. I just tend to follow the majority of examples that don't have issues. I'm attaching my general wire layout. If anyone sees something or could have a rational discussion, please do. I'm all ears.

Dear All, I've changed the original belt driven radiator cooling fan in my GMC Sierra 2004 to an electrical driven type and want to know what is the best alternator to install to overcome the amp loss without adding/modifying alt. bracket/holder or wiring connections please? Regards,

I am currently in the process of writing up a full audio system build document that includes a lot of details. The build document will include a lot of detailed explanations of the gear being installed and include setting up a MiniDSP with Dirac. It's taking me some time to put all the information together, so I figured I would share the alternator section of the document in this post. You can add an upgraded alternator to these trucks, but there is are a few catches that I explain further into the installation process. Alternator Installation Hardware: (1) Mechman High Output 250 Amp Alternator https://www.mechman.com/high-output-alternator-250-amp-silverado-tahoe-suburban-escalade-sierra/ Mechman currently does not show this alternator fits the 2019+ Silverado/Sierra pickup trucks. This does work, but see additional information further into the guide. (1) Stinger Inline ANL Fuse Holder (For Alternator) https://stingerelectronics.com/collections/distribution-blocks/products/inline-anl-fuse-holder (1) Airaid Junior Air Intake System https://www.airaid.com/201-782-junior-air-intake-system (5) Stinger SHW10B 1/0GA Per Foot (5) Stinger SHW10C 1/0GA Per Foot (1) 1/0GA compact ring terminal Need a small ring terminal to use the factory ground bracket with the sensor installed (2) 1/0GA ring terminal Needed for power and ground connections (1) 300 Amp ANL Fuse (1) Roll of heat tape (1) Roll of 1/2" braided wire sleeve (6) 1" Heat shrink tubing at 3" in length (1) Custom built under hood fuse holder 1/8" x 2" Hillman Aluminum Solid Flat Model #: 11303 from Menards Install Process: My factory 2019 GMC Sierra Denali 1500 6.2L shipped with a 170 amp alternator. My past 2014 GMC Sierra had less alternator amperage and I could notice the power drop with only subwoofers added, so for my new system build I was going even bigger and I did not want any protentional power loss. I wanted higher wattage at both idle and normal driving. Also, since I invested so much time and money into my audio system it's worth the additional cost of adding some extra amperage. My new audio system's total max watts is 2,200. Some people may have a much higher watt audio system and the 250 may not be big enough, but adding the 250 will still give you an additional 80 amps, which is more than the factory. GM offered a 220 amp alternator upgrade kit for these trucks, but it would exceed the factory fuse rating, so my guess is it required some type of OEM wiring harness. This wasn't worth my investigation because I wanted more amperage then 220 amps. At this point, I knew I needed to call Mechman to discuss my alternator upgrade needs. After talking to Mechman they informed me my truck had a stretch belt, which limited my alternator amperage selection to 250 amps. At the moment this is the highest amperage these trucks can go per Mechman (As of 9/11/2020). The reason is the higher amperage alternators require a smaller pulley, so the alternator can spin faster to create more amperage. With a stretch belt, there is no extra play for a smaller pulley because you do not have a belt tensioner. The primary issue I ran into was Mechman did not know if the 250 amp alternator would function in my 2019 GMC Sierra 1500 Denali because of the smart charging system. At this time they had no confirmation that any of the 2019+ GM Silverado/Sierra 1500s would work. Mechman gave me the option to give the installation a try and if it didn't work they would allow me to return the alternator without any issue. I knew if this did not work I would be out all the wiring upgrade, air intake costs, and my time. I choose to take the gamble. The good news is I can confirm the alternator does work in the 2019+ GM Silverado/Sierra 1500s, but I do have a little bad news. For some reason GM decided on these trucks they would make an air intake system that stretches clear across the front side of the motor in a huge plastic box, which is probably for some extra emissions reduction. The main issue is they decided to add the support bracket for this large air intake box to the factory alternator. Mechman's alternators are not purpose-built for this truck generation and they sent me one for the 2014-2018 model year thinking it would match up just fine. The alternator mounting bolts and pulley size is correct, but it is missing this mounting bracket. I eliminated this factory air intake issue by choosing to install an Airaid Junior Air Intake System. This system is the least expensive out of all air intake upgrades and it removes the factory large plastic intake box but leaves the factory filter enclosure. I wasn't concerned about the air filter enclosure. I'm not going to go into my reasons for that. You do get a nice cleanable air filter that fits in the factory enclosure. The factory alternator wiring does not have the correct wire gauge and fuse to support a 250 amp alternator from Mechman. This requires upgrading all the wiring between the alternator and the battery. This includes positive and negative wires. I used Stinger wiring for my audio upgrade, so I decided to use the same wire and fuse block for this alternator upgrade. This wire is Stinger 1/0 gauge wire and Stingers inline ANL fuse holder. The fuse holder is added to protect the wire and you in the event of a crash, so make sure you add a fuse holder. If you are using this wire make sure you use a 300 amp fuse on this alternator because the alternator can exceed 250 amps, which will blow a 250 amp fuse. Also, I would recommend having a spare 300 amp fuse and installation tool in your glove box in case something ever happens and you needed to change out the fuse. These are not fuses you can get at your local hardware stores. WARNING: If you are using a different 1/0 gauge wire, make sure the wire is rated to handle at least 300 amps. WARNING: Do not just upgrade the positive wire and not the negative. You can cause major damage or even a fire. I'm sure at this point you are ready to read about the installation and see some pictures. To start I want to show the factory alternator with the air intake box above, so you can see the mounting bracket that comes off the factory air intake. Here is a side by side comparison of the two alternators. The left is the Mechman alternator and the right is the factory alternator. You can notice the factory air box bracket more clearly in this picture. Your first step in removing the alternator is removing the stretch belt. I tried to look up some easy removal tools for the stretch belt, but I couldn't find any information. I tried buying Lisle Stretch Belt Remover/Installation tool and it did not work. My recommendation is to buy or have some plastic door/trim panel pry tools. I used these to remove the belt. Circle 1 works to remove the belt. I used the factory alternator bolt to remove the belt. The removal can be done above the engine. Circle 2 works to install the belt. Mechman's alternator pulley bolt will not work to install the belt because the bolt spins freely and will not move the belt. You need to use on the pulley bolt where the circle 2 is shown. A large breaker bar will help here. You will need to remove the bottom front lower engine splash shield to reach the bolt and slide on the belt. I got the belt most the way on from the bottom and went above the engine and finished spinning the belt using the same bolt/breaker bar while pushing the belt onto the upper right pulley. If you try doing the entire install from the bottom the belt will not seat correctly. Once you pull the belt you will need to remove the radiator cooling fan that sits in front of the alternator to remove the bottom alternator bolt. The fan is installed with three torx screws. I created a custom fuse block holder out of aluminum to hold both my fuse blocks. I used 2" wide aluminum from Menards, which does allow you to bend without heat. If you choose to do this same mounting location it works great and you can use the mounting pin. You will need to expand/cut the plastic top and base where the 1/0 gauge wires run through. I added two 90-degree bends on the engine side of the aluminum fuse block mounting bracket to level out the bracket and give room for the 1/0 gauge wires to run underneath. The main thing to take into consideration is the negative battery terminal. You have to mount these fuse blocks to still allow the ability to disconnect the negative battery lead during maintenance. I wanted to have these fuse blocks run in parallel, but using 4" wide aluminum would cover up the ground and require the fuse blocks to be removed to connect the ground wire. I ran a 1/0 gauge wire back to my audio system's distribution block and ran another 1/0 gauge wire over to my alternator. Note 1: The factory power wire on the alternator needs to be disconnected and not used. Note 2: The alternator will come with a 1/0 gauge terminal you can use for the wire, so you do not need any terminal for this wire back to the fuse block. You will need a standard gauge battery terminal connector to connect the fuse holder to the factory mounting location. Note 3: I used some braided wire sleeve with heat shrink for look and added heat resistant tape on both my ground and positive wires that are near the engine. I recommend adding at least the heat tape to protect the rubber shielding on your wires from potentially melting. You need to run your own 1/0 gauge negative wire from the alternator and use one of the alternators mounting bolt's to hold the 1/0 ring terminal. The ring terminal that came with the 1/0 gauge wiring kit for my amplifier did not have a large enough hole for the alternator mounting bolt. I use a step bit to increase the hole size to fit snug around the bolt. After you get the negative wire ran from the alternator bolt you need to make sure you remove the factory ground wire and connect the new 1/0 gauge wire directly to the mounting point the factory wire installed. I had a smaller 1/0 gauge ring terminal that worked perfectly. Note: Do not connect the factory ground and alternator ground or it may throw off the smart charging system. You need to have only the new 1/0 gauge ground wire connected to the negative battery lead with the same factory connector that holds the sensor. This picture shows me adding some heat shrink to the factory's positive and negative wires. I choose to leave the factory positive and negative wires under the hood. My goal is to remove this system before I trade the truck in for a newer model year, so if this alternator works with that model year I will be putting the factory alternator back into the truck. Here is a picture of me securing the factory power wire. I secured the ground wire near the firewall and there isn't an easy way to take a picture. Since I choose to add the same fuse blocks for my audio and amplifier I wanted to label both fuse blocks. Below are a few pictures of each fuse block being labeled. I added the label to the cover and the fuse mounting point. I did this just in case the covers got installed incorrectly. Here are the final pictures of the installation of the Mechman alternator and the Airaid Junior.

Hey, Iv seen a bunch of posts about setting up a dual battery system and what to use, and i understand all that. Problem is i keep seeing articles about standard relay style isolators and smart isolators (VSR) not working if you have a "smart alternator" because of the fluctuations from the alternator based on driving conditions, and therefore have to go and spend a load on a DC-DC charger. $50 vs $300 Anyone have any issues with their standard relay style or smart isolators on their dual battery setup? Articles below, https://www.12voltplanet.co.uk/auxiliary-battery-charging-in-vehicles-with-smart-alternators.html https://www.redarc.com.au/faq-tech-tips/new-vehicles-technology-can-affect-dual-battery-systems-charging-performanc

I bought this back in... 2013, from a dealer in McKinney, TX (Dallas) for my 2011 GMC Sierra SLT Crew Cab Z-82 Texas Edition. While I was finishing my 3" rear seat lift, Forward Firing Quad 8" 4.5cu ft NET dual ported box @ 31Hz, mounting my 5 Amps, sealing off every small hole in all 4 doors with 1/8" wood and Dynamat Extreme, my Focal Utopia 6W2 Components, Focal K2p PolyKevlar Comps, etc..... I ended up totalling my 2008 Sierra 5.3l the day before I received the Mechman Alternator. A lady pulled out on the 4 lane highway (speed limit 65mph) + middle turn lane, thinking the stoplight (in the middle of nowhere) was red, but it was green, so I never let off my cruise control, whixh was set to 69mph, 4mph over the speed limit. It was cliche. Everything happened in slow motion. I was just going to slam on my brakes and rear end her, probably giving her a 50/50 chance at surviving or swerve. But I saw a young, 4-8 year old girl in the passenger seat, so I swerved. Unfortunately, I hadn't cleaned off one of my wheel speed sensors, so my VDC wasn't working, so Iserved, thinking my VDC would save me from my sudden jerk of the wheel, but itdidn't, lost the rear end, swerved left initially, then right as my rear end got light, went across I front of her, swerved left and went straight across into a tree and rolled it 4 times. She stopped for a second, never got out and drove off. I had numerous people stop and help me. Most. who saw it, was angry at the car who clearly saw it, a few guys said I should have just ran her over. So anyway... my Mechman G-Series 270a Alternator with the optional $65.00 Billet Aluminum OverDrive Pulley came in the day after I totaled it. The OverDrive Pulley does two things. First, it lightens the unsprung rotational mass, therefore making it much easier to spin which equals more horsepower. 2nd and most important is that it allows much higher output and lower RPM's. I no longer need it as I never purchased another GM vehicle. It just happened that way. I ended up getting a Nissan Armada and now I'm in a 2011 Nissan Titan Pro-4X Crew Cab that I'm lifting 8" in the front & 9" in the rear. I believe I paid $600 total for it as I have the receipt. This fits all GM vehicles from 2004-2014 4.3l, 5.3l, 6.0l, 6.2l and many others such as 3.4l, 3.6l etc.. It fits vehicles with the 2-Pin Alternator Wiring Harness Plug. The alternator I was upgrading was the Optional AC Delco DR44 145a alternator, which is for sale also. Never installed, never mounted, never been inside an engine bay. I do know that the smaller pulley does not require a new belt. I paid $499 + $65 for the Billet Aluminum Overdrive Pulley + $20'ish for Shipping For Sale Price: $400 + Actual UPS Fully Insured ($500) Shipping

2018 Silverado 2500 LT 1,300 miles truck during the day shows volts at 12.5. I can turn on ac full blast, radio and defroster and colts stay at 12.5 all day. When driving volts stay at 12.5 when I’m rolling and foot of gas mpg gauge goes up to 99mpg then will charge at 14volts as soon as I hit the gas bolts drop to 12.5. And night when headlights turn on truck will charge at 14 volts. First two times truck was taken to dealer they said nothing is wrong now the third time they tell me that’s not normal and change alternator and never fixed the problem still in the shop. Anyone have same issues or volts stay around 13.2-14.5 volts all day and night

Has anyone hooked up dual alternators in a 1500 Silverado? I'm dealing with a 2011 that has a 5.3. Apparently GM used to have a factory plate for older generations of the Silverado to add the second alternator. I've found a 3rd party selling an adapter plate, idler pulley and belts for $215 but it seems awfully pricey for what they're selling.

I'm planning on upgrading my truck with a simple audio system, maybe 2 LED light bars, plus accessories. 1.For the audio system Simply replace all the stock speakers with higher quality plus an amp. For the head unit, I'm looking into the 10in screen models. Also I found some bed storage bins that come with speakers as well which are perfect for tailgating. 2. LEDs A light bar, maybe 2, and some other lighting that I haven't decided on yet. 3. Accessories... Train horn+air hose kit that comes with certain models. I have a solar panel that I got on ebay that I use to maintain the battery since I'm always stopping and going due to my work. But I'm planning on upgrading the alternator, big 3 ground kit, and a second battery. What do you guys think??

New guy, just got out of the truck and heard this high whining sound that eventually goes away as it warms up. Truck has 303,563 so far and I hope to go at least 500,000. I'm guessing alternator as I feel a grinding when I touch it as it makes the noise. Original engine and most parts. Trans at 165,000 nothing else major

Hello everyone, new member here from Tucson. I recently purchased a Yukon, and i suspect a bad alternator, but i am new to TBI so this may be normal behavior. When cold, im pulling a solid 14v, as the truck warms up, the voltage drops to 12v. With lights and a/c running its 11v, and it seems to have nothing to do with rpm. The truck has a new 600/750 CCA battery. Is this normal behavior for a 350 TBI? Thank you.

So it started happening to me about a week ago, my truck would just randomly not start. When it first happened, it would struggle to turn over. I said no problem and just bought a new battery for it. About 3 days after that, I went to the store and was only in there for about 2 minutes and got back in my truck and out of nowhere, nothing happened, not even a click. I checked my connections as best as I could, and eventually had to get jumped. Tried it again as soon as i got home, turned it off, immediately tried to turn it on and once again, not even my dash lights were coming up. I jumped it and took my negative off to see if it were the alternator or not but it kept running. Any thoughts?

Greetings, all. ​I'm still learning here and am wondering about something I ran across recently. (Sincere thanks to everyone on here who has already been a huge help to me thus far!) I understand that the increased-power/heavy duty alternator (part number 22949467) appears to have made its way into many 2015 CrewCab models and other models with the snow plow-prep package. It seems tied to RPO 5W4 (which, in several sources I've researched, ties back to "VEHICLE SPECIAL SERVICE, MUNICIPAL" - makes sense for a snow plow-prep package). ​I scored a fantastic deal on one of these units for my 2014 Silverado LTZ Z71 DoubleCab 4X4. Being an LTZ, my Silverado has most of the current-drawing goodies. It also is about to have the factory Kicker subwoofer upgrade kit, an on-board air compressor (Viair 40049) and a full front/rear dashcam set-up with active/passive monitoring. I've also just paired all of this with a brand new AC Delco AGM deep-cycle higher output battery (P/N 94RAGM). In other words, all of the further current-drawing goodies are here and ready to be installed when the weather here gets a bit warmer. Are my electrical upgrades going to be good enough to support an already high current use truck with an extra draw or three?

Hello, all. I have installed several sets of off road lamps (14 55w 12v lamps in total) on my H2 (Same engine set up as a 2001-2006 GM 2500/3500 Silverado/Sierra) , and notice a power draw when I have all of them on at the same time (lights dim etc). It has been recommended to me to install a more powerful alternator to compensate for the new power needs, rather than going with dual battery set up at this time. I believe the factory alternator is a 145amp Delphi. What is the power output at idle (500rpm)? I am looking at replacing it with one of two aftermarket alternators rated at 225amp and 250amp. Which would be better for my application? TIA. https://www.amazon.com/LActrical-OUTPUT-ALTERNATOR-CHEVROLET-WARRANTY/dp/B00C3RDNZC https://m.summitracing.com/parts/pwm-48237/none/images

Hey Guys, I have a 2006 Silverado 1500HD 4WD. Since I bought it, the headlights and ALL interior lights(cluster, radio, cabin lights) have dimmed/flickered while the engine is running.I Figured it was the light switch, and i would replace it when i got to it.... Yesterday, I was idling at an intersection, and all the electronics started seriously dimming and then died. the engine was still running(BARELY) and i was next to a grocery store so i limped it in to the parking lot with the power in and out, and it died. But before it died, the dash read "SERVICE CHARGING SYSTEM" & "SERVICE BRAKE SYSTEM".... Thing is, I just re-did the brakes less than a year ago, so I'm thinking it's all related and the brakes are fine. So far I have checked and cleaned the ground to the frame(down below the battery.... are there other points in need of cleaning??), both battery terminals, the connections in the little red fusable link box to the alternator, and the connection going into the alt. from that box. I also took the Alternator into O'reilly first and it passed. My old battery was a little low, so i just bought a new one as well. The BRAND NEW battery is testing 13.5 while running, with a load or without a load, and tests around 12 while off. I saw something about a MEGA fuse on the passenger firewall, but it is not there on my truck. I watched a YOUTUBE video on a '04, and so i know where it is on that model but mine isn't there. Has anyone had this problem, and WHAT WAS YOUR SOLUTION?!?!? Thanks in advance. EDIT: after typing this something occurred to me.... the previous owner had a remote start system installed, which also locks and unlocks the doors. My FOB died so i wasnt using it for about 6 months, but started again about 2 weeks ago. I did not use it at all yesterday or anytime for maybe 3 days before the issues.... could this be causing it? I mean, I'm not using the system while the issues are popping up, and it's low-voltage so my gut says it's not the problem, but maybe?

I have a 2002 GMC Sierra 6.0L 2500HD that i am trying to sell. The alternator went on it last week so i replaced it with a reman that turned out to be bad, it had low voltage coming out of it when i tested it (3.5-4V). They replaced that one with the same thing and tested it first to make sure it was good before handing it over. I installed that one and am having the same problem. The truck runs until the battery dies with no codes with the alternator averaging 3.5V of output according to my voltmeter. I am getting relatively pissed about this since i have replaced many an alternator and have never had so much trouble. Any help would be appreciated, cant find any threads that are specific to this problem.

I'm thinking this is an alternator issue but wanted to get other ideas. My 2002 Silverado has 160k miles on it. This is the original alternator. When I first start it after it sits for a few hours, basically when it is a cold start. The battery light comes on and stays on until I bring the rpms up. What is also weird is I have a ScangaugeII installed and the display will not come on until I bring up the rpms. When I first start it, the volt gauge on the dash is showing 10vdc. When I bring the rpms up it goes up to 14.2 and the ScangaugeII comes on and it shows 14.2 as well and the battery light goes out. From there on out it runs fine. No other issues with the light coming on. Driving it around the ScanguageII shows 13 to 14vdc. All my electrical connections are clean and tight, as well as all the grounds. Do you think this is an issue with the regulator inside the alternator? I was going to pull it off and have it rebuilt. Not a fan of getting one off the shelf at AZ,AA, CQ or O'Rileys.

I have a 2002 S10 with 2.2 4-cyl. I have replaced the battery and alternator, and the new alternator will not charge the battery. What do I need to check? The cables and ground are clean, and I get the full 12 volts when not running; but get no charging output when running.

I have a (new to me) '06 Sierra - in my work it spends a lot of time idling with little or no electrical load (parking lights only). When I first start up, and on short journeys, the battery voltage goes up to 14.5 - 15V every time, however I've noticed that when it's been idling for a while (30-40 minutes with short moves every 5 minutes or so) that voltage drops to 13-13.5V - if I shut off and restart the engine, it goes back up to 14.5V+ - and the following day it's right back up to 14.5V - 15V I'm not seeing any other electrical issues (lights stay bright, always starts well, passed the charging test at NTB) so my question is whether this is normal as the battery approaches full charge or if this is a symptom of a problem brewing? Thanks!

'99 K1500 5.7 W/AC I've got dual batteries with a Hellroaring separator/combiner and I recently started towing a travel trailer that has dual batteries, so I need to upgrade my original alternator to (at least) 140 amp. I've read the connectors are different (original - oval, 140A - rectangular), and I might need a different serpentine belt. I don't know if that only applies to parts from certain manufacturers, or if it's the nature of the upgrade. I'd have to order one locally to get a look at it, but if I order one I want it to be the right one. Has anyone here done this upgrade, and can you share your experience?

I have a 2004 Chevy Silverado. At times it won't start and I have to tap on the alternator of a few times and then it will start. I was told that it might be the bearings sticking and ready to go out. So I replaced the alternator with a new one. Only problem, I have the same problem. It still won't start at times and I'm back to having to tap the alternator. Please help me in finding the solution.

I've been having a problem with my 05 4.8l v8 Silverado that I'm hoping someone here can shed a little light on. So, friday morning, started my truck to go to work and it kind of lagged a little bit, but started. By lunch time, I went to start it and all it would do is click (battery). So I jumped it and it started right up. Driving home (about an hour or so) I noticed the battery gauge would fluctuate, 12-15v. So I chalked that up to it being an alternator. Auto parts store confirmed it and $180 later I was on my way home to fix what I perceived to be the problem. I replaced it the following morning, kind of lagged a little bit when I first started it but it ran just fine. Drove around for about an hour or so to give it a chance to charge the battery and noticed that the gauge still fluctuates. Took it back to the store and they said the alternator is fine. The truck runs fine but when I start it, it bogs a little. Not sure yet if it is still draining the battery. What could be the problem? Do I need to reset the computer? What would be the best way of doing so? Is it a grounding issue? Thanks, Edwin Secrist

Hi All, I have a 2006 Sierra 2500HD, 6.6 duramax, 4x4. It is my everyday work truck that goes out rain or shine. I am looking to put a dual battery system in the mobile office/darkroom that is on the back. I am running an ac (inverter) and a dc system curently off the start battery. We have been having issues with the trucks computer because of the draw from the original system. I want to put a new system in with dual deep cycle batteries in the back. I know I want to put in a isolator and fusable links in the proper places but I have no idea how big of cable to run to the back and how big (amps) I need to make the fuses, isolators, switches, ect. I would also like to make the new system easy to turn off and on so I do not kill the new deepcycle batteries every time I use the truck and then leave it overnight. Can anyone help me sort through some of this fun stuff??? Thanks Trevor