Gentlemen (and ladies if there are any),

I've been having an intermittant message on the instrument message screen which says that the battery is not charging. It only happens on a cold start, and not every cold start. The Tech at the dealer said it could be the glow plugs if they stay on for 18 seconds (he had a TSB about that particular problem). Well, the glow plug light barely stays on even a second. So, I don't believe it's that.

The Tech is stumped at the moment, and they've actually reproduced it once, so they know I'm not smoking crack. Now that he's seen it, he doesn't believe it's the glow plugs either, but he doesn't know what it could be.

He's done a full electrical charging diagnostic, with everything turning up good. Batteries at 900 CCA and alt at 13 amps.

Even if there's a drain on the electrical system (something hard-wired to the batteries) I wouldn't think it would make the computer think there's a charging problem. You should be able to run the radio, lights, etc. in the ACC key position with no problem when you start the engine, right? I mean, it shouldn't make the computer think that the batteries are not receiving a charge, should it?

Has anyone experienced this, and did you find out what it is and how to fix it - if fixing is possible?

Thanks,

J

My truck does the same thing. Possibly the glow plugs are pulling the batts down just before you crank it over. I checked my batts and atl all was ok. I would not be overly concerned about it. My dealer was able to reproduce the problem but not find a solution for it.

There is a GM TSB on this and it is to be considered normal if it only occurs on start-up, according to them. I haven't seen this on my truck , but I am considering adding the dual alternator option to mine to insure no future problems...
Ed

The TSB that I've seen regarding something like this is when the glow plugs are on for 18 seconds and in cold weather. Well, the temps here in southern TX aren't anywhere near cold enough for the glow plugs to be on that long.

I just received my truck back from the dealer. They replaced my instrument panel thinking that was the problem. It wasn't. Later today I had the same message pop up.

I have wanted the dual alt setup for awhile, I have a couple of other things I need to pay for before I buy the kit. I don't think it will fix that problem though.

Thanks,

J