Battery not charging

[Jrgunn5150]

Today on my way home, in the rain, I noticed my lights dimming and getting brighter. Then I noticed my battery not charging light on, and my volt gauge was down under 12v. I intentionally drove through a pot hole, and the lights got bright and it started charging again, then popped back off.

So, I got home, got my multi-meter, checked for voltage at the back of the alternator, got the same battery voltage, down around 9 now.

So I fussed around with relays and cables and whatnot, and had to jump it with my truck to get it to restart. Cleaned all the cables and connections, never got the thing to start charging again. I did find a cable that seems to not be hooked to anything, but it also seemed to be intentionally tucked up in the harness, I looked at two more Trailblazer's and they also have the same wire unhooked in the harness, so I don't think that's it.

I'm going to take the alternator down to Autozone in the AM to have it tested, but at this point, I'm pretty sure it pooped on me. My question is, is there anything else anyone can think of I should look at? And is there any upgrade that fits where my DR44 is?

[Jrgunn5150]

Sent from my SM-G900V using Tapatalk

[KingBird]

That wire powers your trailer plug. It's provided by GM but never hooked up from the factory.

[Jrgunn5150]

That wire powers your trailer plug. It's provided by GM but never hooked up from the factory.

I figured it was for some other platform or something, three Trailblazer's can't have had the same wire tucked neatly away lol.

FWIW my alternator was bad, sounded like it was full of rocks on the tester.

[KingBird]

It doesn't need to be hooked up unless you have a trailer with auxiliary power. For example, we had a flatbed hydraulic trailer with a winch attached, the trailer was wired so that the towing vehicle charged a car battery that ran the winch while you towed it. It wouldn't work on a Trailblazer, unless that wire was connected.

[Jrgunn5150]

Ha, that's good to know, I've been rigging up a rear mount winch.

[Trail X]

Sounds to me like it could also be a bad connection - sometimes a chassis ground.

Let us know what you find about the alternator.

[Jrgunn5150]

Sounds to me like it could also be a bad connection - sometimes a chassis ground.

Let us know what you find about the alternator.

I feared something like that too, but so far a new alternator has been charging good, with no further glitchiness

[DirtyBacon04]

Ah, yes.
The infamous red wire...
Lucky Roadie didn't catch the question first. You'd have been Roadie-mocked. At least a little bit...

[Jrgunn5150]

Ah, yes.
The infamous red wire...
Lucky Roadie didn't catch the question first. You'd have been Roadie-mocked. At least a little bit...

Well i wouldn't feel like I made it as a Trailblazer owner if that didn't happen lol.