SOLVED! 04 Trailblazer battery light issue

gica

Original poster
Member
Dec 25, 2012
135
Cali
So I did some work on the cooling system, had to remove the alternator and because I didn't disconnect the battery negative I touched the wire that goes from the alt to the battery against some ground it sparked and when I put everything back the alt wasn't charging the battery and I had a message on the dash battery not charging plus red warning light on the top right corner of the dash. So I checked things out and from a sudden inspiration I checked the connector on the alternator and sure enough one wire was only being held by the rubber insulation. So I soldered it back shrink wrapped the soldering joint and I got the alt to charge the battery at 13.9 again.
But on the dash I still get the battery not charging message and the red battery warning, the gauge though reads accurately at 14V. I did not check the second wire that goes to the alternator connector so before doing that does anybody know about this issue, or does anybody have a schematic of the alternator wiring? Thanks in advance
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
OK here's the diagram, so I don't remember which one I fixed but I think the field duty cycle grey wire not the red one. I also have not checked fuse 24 which is 10A. Very strange that the gauge shows 14 but the message center and the red light are on. The alternator was not on the car when the spark occurred.
 

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Blckshdw

Moderator
Nov 20, 2011
10,665
Tampa Bay Area, FL
OK I figured it out

For future people who might have the same problem, and come across your thread, can you share what the problem, and fix was?
 

gica

Original poster
Member
Dec 25, 2012
135
Cali
I first found and repaired the red wire on the alternator connector, it provides the alt with power to start charging the battery, so that fixed the gauge and the charging and I also found and repaired the black wire and that fixed the battery not charging and red warning battery light. Pretty much the connector was the problem
 

Hlewz3

Member
Apr 9, 2019
1
Arkansas
Hello Gina. I have an 04 TB and I’ve replaced the alternator and battery. Still the battery not charging so now I’m tracing the two wires throug the loom. Is there any other areas to look at? Also the data cable that’s bolted to the alternator...is that a concern that I should be looking at as well? Thanks

My apologies. Gica...my iPad is thinking and spelling for me incorrectly.
 

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