BigBlockBurban454

Howdy fellas, sorry its been a while. Things get crazy with work sometimes and we make the repairs, and head straight back to work while forgetting the people who helped us figure it out. Thats on me. Simply put, this was indeed a bad battery connection issue. And you guys were right basically from the beginning. After taking a day off work and testing wires and terminals for a solid 8-10 hours straight (about a year ago now), i finally found the intermediate break. The source ended up being the positive battery terminal, but not in the way you would expect. This truck has factory crimped battery terminals to the primary wires, with maybe 3 inches of sleeve crimped down (thats a lot and good). So i didn't even think to look at the battery terminal to wire connection itself. I got desperate, as this is my work truck, after checking connections all over the truck. Fuse boxes, ignition cylinder, grounds, everything. So I cut the battery terminals off, and HELLO! A cloud of corrosion fell out of the positive battery terminal factory crimp connection, where the terminal is crimped to the positive wire. I cut the connector open, as is standard in my line of work. If something fails, you have to do failure analysis. And sure enough, the wire and connector were completely corroded out inside, beyond view, with no obvious evidence before i cut it open. Sorry I dont have photos, I was trying to get the truck back on the road lol. Replaced the connector and to this day, over a year later, not a single electrical hiccup with this truck. Yall were right, bad battery connection. So kudos to the fine gents of the forum because its the last thing i was thinking. As a state licensed electrician, bad battery connection?? No way, ive checked it over and over. Boy was I wrong. Im just happy shes running like a top now. Thanks again to everyone who put in the knowledge and two cents into this. If not for that, I probably would have never cut those battery terminals off and found the issue.

4x4? If so we have the same parts. My guess would be wheel bearing, especially if you have bigger than stock tires on it. They are defiantly worth a look at, lots of videos online to show you how to inspect if you don't already know. Another thing to check is if you leave the 4x4 in auto, it will keep the front hubs locked. Maybe the CV axles are causing the issues or worst case scenario the diff. You can find videos showing you how to inspect those parts as well

For reference, this is my alignment report for my 1 inch strut lifted 2012 Sierra 1500 4wd after replacing the upper control arms

I definitely agree with the others, I didn't even think about z height for alignment. So I agree, get some bolts, chase those threads, and install them. Put them in with little tension if you don't have a torsion key compressor, take it to the alignment shop and make sure they know the situation. Looks like a problem solved to me

Well again it sounds strange to me, but since your the original owner, you know your truck. The missing bolt is curious, but if the ride height is about right and she rides nicely, then without the bolts is just fine. If you wanted to level the truck, adding bolts could be a cost effective way to do it as long as it doesn't stiffen the ride up too much. Gotta be careful with adjusting those torsion bars. Ive honestly never had my hands on a 1500 HD model as they are much more uncommon, so I cant speak for certain here.

That certainly sounds strange to me. Does it have a lift or is the suspension stock? Does the front end look too low? How does it ride? Being a 1500 HD, the front end should be similar to stock, but it may have more rake with bigger leafs in the back

The white bed light is staying on, not the brake light? Does the brightness of the bed light change when the brake is applied? Resistor should not be needed for the bed light. Sounds like you have some sort of electrical issue. Does the brake light operate normally? By normally I mean no running light, it's completely off until you hit the brakes. And does the brake light do anything when you run turn signals or hazards? I feel like voltage is jumping between wires somewhere maybe

I have gone trough the battery connections and cleaned them up well, but I will certainly give it another go BarryKH. And I like the dielectric grease idea diyer2, not sure why I never thought about it. I use it all the time for electrical connections at work! I've been planning the big 3 upgrade as I want to install a 2000w inverter in the truck, so maybe I should just go ahead and do it because that would mean all new primary connections. I also have ohm tested the ground between battery and block, battery and body, and battery to frame. They all test out good. But I like your idea asilverblazer using jump cables to introduce a new ground path for testing. I will try this next time she doesn't have power before I mess with the battery at all, see if she comes alive. Thank you for the input guys! My biggest fear was maybe some computer malfunction. Hopefully it is just a bad connection somewhere. Its just strange because when it does have power, I know the connections are solid because she turns over fast and fires instantly. I've also used my thermal camera to look for hot spots at connection points, I didn't see anything alarming. Funny enough, she has had no power issues today. But I probably just jinxed myself... Ill do some more testing this evening too see what I can find. Thanks again!

I am new to this forum, so I apologize if I have placed it in the wrong area. My work truck for my company is a 2012 gmc sierra 1500 ls with the 5.3l. This truck was plauged with electrical issues since I bought it 3 years ago, all of which I thought I fixed being a shade tree mechanic my whole life and an electrician by trade. A few days ago, I went to fire up the truck in the morning. I put the key in run for 3 seconds as I always do, and attempt to crank with the dash fully lit up. This time the second I put the key in crank, I heard a click and the truck lost ALL power. Pull the key out, put it back in, nothing. No dash, no chime, not even power to the cigarette lighter. I pulled the negative cable, reconnected, and all was normal. The following day the same thing happened. Pulled the negative and reconnected, all good. Went to the gas station, did it again when trying to start. But this time, power came back when I removed and reinsert the key. All good. The following day, started just fine in the morning. Same deal as the previous day, wouldn't start after gassing her up. Pulled the negative and reconnected, still no power. I had to pull and reattach the negative 3 times before I got power back and it cranked just fine. At this point, I'm using the different scenarios to try and narrow down the problem. But today, it was really strange. When leaving my jobsite today, I noticed that as soon as I put the key in accessory, I lost all power. I have a Bluetooth receiver for my stock radio, plugged into a constant hot cig lighter socket. The charging light was on until the key goes to accessory then it went dead. I pull the key, power comes back. Put the key back in and turn to accessory, loose power again. I did this about 15 times, same result. If the key was turned at all, I had no power to anything. With it off, I did have power to constant hot systems. I pulled the battery negative 5 times to finally get it to maintain power with the key turned, and finally it started completely normal. Anybody have any ideas? I have 2 optima yellow tops less than 6 months old. There is absolutly zero corrosion on any major wire connections, and all connections are tight and adequate. I checked with my ohm meter. I did notice today when I shut the truck off, I heard a pop come from the speakers. Truck ran no issues for the whole drive, but when I shut it down it killed power to everything much like when I attempted to start it. I was thinking ignition cylinder, but zero power with the key pulled does not support that. I would really appreciate any input for this!! Like I said I am an electrician by trade, but automotive is quite different with computers and what not involved 2012 GMC Sierra LS Z60 5.3l LC9 4x4 1993 K2500 Suburban Cheyenne 454 4x4