2003 silverado intermittent running issue
 

Hey guys, I am new to the forum and wanting to know if anyone has come across this before. This is on a 2003 1/2 ton silverado, 5.3 litre.

Last Sunday evening I started my truck to leave my sisters and the truck would hardly idle. If you tried to give it any gas it would stummble and die, kind of like it wasn't getting any fuel but their neighbor said black smoke was pouring out the exhaust. While all this was going on the hazards would light up but not flash on the dash and in the rearview mirrors, the information display would say 'Service 4WD', the chime was going off, and the brake light would come on. If I shut the lights off it would run fine so I thought maybe the battery was bad.

I guess I need to add there has been a couple of times while driving over the last six months this happened and the service 4wd, the chimes, hazards, and brake light would go off but for just a second but I never felt the truck stumble.

I replaced the battery and it ran fine, it sat for about 5 days and on Friday I began working on moving some trailers around and it started doing it again. I ran it over to a local shop to have the alternator tested (the dash always showed about 14V and it tested fine but would not do it while it was there.

There are no fault codes getting thrown, any ideas or has anyone seen this before? Thanks and I appreciate the help!

Hmmm that is weird. Looks like its gonna be a fishing job, meaning try to catch it while its doin it and have a scanner ready. But it really sounds like an electrical problem.

Yea, it is going to be tough. It did it again today but for about 5 seconds then started running fine. I am leaning more towards a voltage problem myself. Today it wouold idle fine but all the chimes, and indicator lights were going off, when you would put it down to drive or reverse it would stumble and die.

I think I remember someone had a similar problem like this. I think it was either their ignition switch or the gauge cluster.

I'll check the ignition switch and hope it't not the cluster lol.

I just got off the phone with a friend of mine that is a tech at a chevy dealership, he thinks it may be an issue with one of the grounds. I checked both cable ends at the battery, the junction block between the alternator and battery, and the post on the back of the alternator. He said there are two ground straps on the back of the engine and 2 on the underside of the drivers door and thinks it may be a problem with one of those. I'll let you know what I find but it will probably be last in the week before I get a chance to look into it.

im on board with the bad ground idea. i'd clean them all, sometimes they can be dirty without looking dirty. they get almost a hazy type of layer on them.

Well, good news, I figured out what the problem was. I told you all before I thought it was the battery and I replaced it, five days later it started to do it again.

Well, someone smack me now cause I'm an idiot, with a new battery it still can't get the full 12V all the time if you don't tighten down the positive battery cable!!! :eek:

I found that last Thursday when checking all the grounds and it has not done it since. Thanks for all the help!!