Intermittent Electrical Problem

[keelerjr12]

I did a search and read what I could but was hoping anyone could help me out with this problem:

 

Bought a 2007 Silverado 1500 (47k miles) about 4 months ago and haven't had a problem. The last week or so, usually once a day I will go out to the truck and notice the clock is reset. I'll go to start it and the starter solenoid will either click or not click, but then the truck won't start. I release the key and try again and it starts right up.

 

I had the battery and alternator checked at AutoZone and they said they were both good. The battery is almost a year old. I have checked the connections, cleaned them, and retightened them. I'm not sure what else it could be.

 

About 2 months ago I ended up spilling oil in the back seat and it ran down the side of the paneling and and made its way too the front of the truck. I ended up removing all the wiring that runs along the side of the truck (underneath the panels) and cleaned them and retaped them. From what I could tell no oil made its way to any of the connectors. I'm just wondering if I did have a short somewhere along there or at the connectors that lie directly below the parking brake, if that would cause me to have problems.

 

Honestly, I don't think that's where my problem is being that if the oil was going to short anything out it would've done it by now. Thanks!

 

Update: The connector for the ground cable to the battery and the terminal itself is incredibly hot. This makes it seem like it is a bad cable causing a short. Or could it be an alternator or starter that is getting ready to go?

[waumo1]

Your update tells me you have identified the location of the problem. Now you just need to determine if it is the battery or the negative cable/connector. I'm betting on the cable/connector.

 

You could put a voltmeter from the negative battery post to the vehicle body, turn on headlights or start the vehicle and watch meter for a significant voltage reading. Or turn on the headlights with the truck not running, wiggle the cable at the connector and watch for flickering lights. Just be aware, that if you cause a spark near the battery, you can cause the battery to explode. Always wear safety glasses, gloves, etc when messing with a battery. If you don't know what you are doing, take it to a mechanic.

[keelerjr12]

Thanks for the reply. I went out and did what you said. I started it up, turned on the lights, and wiggled the connector/cable, but I got no flicker. Also, I wiggled the ground cable throughout the truck and didn't get a flicker anywhere. However, the connector was hot (too hot to touch). Now I'm just wondering what is causing this. Loose battery post maybe? Like I said, it's only a year old.

 

Update: I started up the truck, disconnected the ground cable from the battery and checked if it got hot. Was cool to touch. I then reconnected the ground cable to the battery and it heated up within seconds and was, once again, too hot to touch.

[waumo1]

To clarify, you would need to have the lights on with the truck NOT running, and check for loose/intermittent connections. Once the truck is running, the alternator will supply power for the lights, etc.

 

When the negative connector gets hot, can you tell if the source of the heating is the connector/cable itself or the battery post?

 

If I was there with a voltmeter, I could solve this in seconds but from here it is guessing. And I'm guessing you have a bad cable to connector junction. If it is a simple cable, you could get a new battery connector and put it on the cable - or just replace the cable.

[keelerjr12]

I did it with the truck off and with it started and neither time did I get any flicker. Also, it feels like it's heating up right at the connector. At least that's where it's the hottest. I'm going to pick up a multimeter and see if I can pinpoint it any better. What should I be looking for with the voltmeter?

 

Also, the connector is the kind where the cable is crimped and then slides into the connector. I believe GM has had problems with these in the past.

 

Update: I went out there on my break to check it out again. The only place that it's getting hot is at that connector and about 3-4 inches of the both wires that crimp into the connector. I wiggled it but I didn't get any flicker again.

[waumo1]

I would just replace the cable or a cheaper option might be to cut off the terminal and install another terminal from an auto parts store to the cable(s) like we always did in the past. I'd check on what a replacement cable costs from a dealer before kludging another terminal, etc on the old cable.

 

I'm assuming you don't have an extended warranty but if you do, let a dealer replace it.

[txab]

Replace the cable or cable end. Then if the problem still exists, replace the battery

 

And don't connect/disconnect the battery cable while engine is running, unless you like frying electrical components

[keelerjr12]

Thanks for your help guys. I tried another battery today, it didn't get quite as hot as quick but it still had trouble starting. The alternator tested fine with my voltmeter so I believe you guys are right about the ground cable.

[tmoney82]

I had this problem with my 08 Denali. I end up changing out my negative cable awesome didn't have a problem in 2 years. The problem has come back and I'm thinking it's the positive cable. I recrimped it and has not had the problem since.

[ujtruck]

Connect a heavy duty jumper cable, and then start the engine to see it’s a bad battery
or cable

[ujtruck]

Gentlemen you can't think your ground cable or batter is defective, you have
to test it, you will need a good test light and DVM (digital volt meter) and
also if you have AMP meter you can test the Load of the starter motor or head
lamps how much juice it’s sucking

 

What we need to do here is perform Voltage Drop Test – just having test
Equipments (Multimeter / AMP meter) does no good, you have to know how to use
it

 

According to Josh -> “the connector for the ground cable to the battery
and the terminal itself is incredibly hot”.

If you are an Electrician – Too Hot = way too much resistance in the circuit

Next we need to isolate that, defective location or components

Check for short circuits and bad components

Please remember in order to do voltage drop test, you must load the Circuit –
why? Ok we have truck with a good Battery, but ground cable is sucks, now we are
going to ohms test this cable with a DVM, yes, indeed it will show us cable is good,
but inside that cable, most of the copper strands are broken (or corroded),
just few copper strands carrying all the voltage

So in situation like this measuring ohms in the cable not going to help and
we have to do Voltage Drop test

 

 

[ujtruck]

 

 

 

[keelerjr12]

So I ended up replacing the connector a few days ago and everything works fine. Couple dollar part that was fixed in about 2 minutes caused a number of problems. The weird thing is when I cut the old connector off, it and the wires looked perfect. So for some odd reason it was causing me to get a bad connection.