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2004 chevy trailblazer_lt
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Discussion Starter #1
Does anybody have a resource where I can find all of the ground locations for the Trailblazer? Looking to check each one and clean them up so I can rule out grounding as an electrical issue (dimming headlights). I have also heard that the Secondary Air Pump may have a bad grounding condition.
 

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2005 chevy
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I don't know if there's something specific that lists/labels all of the grounding points like that. Possibly one of those beefy manuals? :undecided Maybe when the rest of the country wakes up, someone will chime in. If there isn't such a thing, a more time consuming option would be to go through the CHASSIS WIRING-LAMPS section of Compnine.com and you can follow the wiring in each exploded drawing until you found the grounding points you wanted to check.
 

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2006 chevy trailblazer_ls
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Here are the ground listed in my service manual. Some you have to look for, others are clearly labeled. These are for the 4.2 and 5.3L engine. I have also included the short and long wheelbase. Be aware that the grounds may have changed from the early to late model years. Was about 20 pages I had to scan.

I hope I can fit them all in this post.

Hmm. It seems one of them got lost across my network. I will add the missing scan later on in the day.
 

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2004 chevy trailblazer_lt
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Discussion Starter #4
Here are the ground listed in my service manual. Some you have to look for, others are clearly labeled. These are for the 4.2 and 5.3L engine. I have also included the short and long wheelbase. Be aware that the grounds may have changed from the early to late model years. Was about 20 pages I had to scan.

I hope I can fit them all in this post.

Hmm. It seems one of them got lost across my network. I will add the missing scan later on in the day.



Excellent!

Thank you very much. Now I have something to do this weekend.
 

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2004 chevy trailblazer_lt
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Discussion Starter #5
Current Draw from somewhere

Hi Everyone. Some new developments in my quest to find out what the headlight flickering is about. Stopped by my mechanic and he did some load testing on the current battery and alternator and they both tested out as good. What he did notice was that with EVERYTHING turned off (engine, radio, blower fan, lights,key out of ignition) that there was still current draw of .68 amperes. He would accept .2 amps or less and said it would be time to start taking a look at bad grounds or other wiring issues. Anone have any ideas as to where to start?

Thanks!

Chris
:hissy:
 

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...said it would be time to start taking a look at bad grounds or other wiring issues. Anone have any ideas as to where to start?
...
Did you look at any of the grounds from Wex's manual?

Tracking down parasitic drains looks like it's always a PIA from the threads I've read. A lot of people start by disconnecting the OnStar module under the rear seat, as when that fails, it doesn't go to sleep like it should. Not sure how that would cause flickering headlights.

Another thing you can try, disconnect the megafuse in front of the underhood fuse block, and then see if there's still a draw or not. If the draw is gone, then you know the culprit is powered by the rear fuse block. If the draw remains, you know it's something powered by the front one. Looking in your manual, you can figure out what those items are, and troubleshoot further as you see fit.
 

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2004 chevy trailblazer_lt
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Discussion Starter #7
Did you look at any of the grounds from Wex's manual?

Tracking down parasitic drains looks like it's always a PIA from the threads I've read. A lot of people start by disconnecting the OnStar module under the rear seat, as when that fails, it doesn't go to sleep like it should. Not sure how that would cause flickering headlights.

Another thing you can try, disconnect the megafuse in front of the underhood fuse block, and then see if there's still a draw or not. If the draw is gone, then you know the culprit is powered by the rear fuse block. If the draw remains, you know it's something powered by the front one. Looking in your manual, you can figure out what those items are, and troubleshoot further as you see fit.
Good starting points. Thanks.

I did look at the few grounds I could reach, all seemed clean and tight. Wex's diagrams are great. there is a TSB for a ground modification (new ground post and nut somewhere on the frame) for the TBlazers but I'm not sure of the location of the ground. I need to find out more about that TSB. The number is 10-08-45-001A and came out on June 6th, 2010.

Thanks!

Chris
 

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Wex - thanks a lot :thumbsup:. That's a keeper to tuck in my trailvoy file for future reference.
 

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2006 chevy trailblazer_ls
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Wex - thanks a lot :thumbsup:. That's a keeper to tuck in my trailvoy file for future reference.
No problem at all. Even if one is not having a ground issue, its informative to be become familiar with your vehicle platform.
 

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Discussion Starter #10
Did you look at any of the grounds from Wex's manual?

Tracking down parasitic drains looks like it's always a PIA from the threads I've read. A lot of people start by disconnecting the OnStar module under the rear seat, as when that fails, it doesn't go to sleep like it should. Not sure how that would cause flickering headlights.

Another thing you can try, disconnect the megafuse in front of the underhood fuse block, and then see if there's still a draw or not. If the draw is gone, then you know the culprit is powered by the rear fuse block. If the draw remains, you know it's something powered by the front one. Looking in your manual, you can figure out what those items are, and troubleshoot further as you see fit.
Ok. Followed the recommendations of disconnecting the megafuse in the fuse block (engine compartment) and had Advanced Auto run the electrical system test and the current draw was at zero. Down from .68 amps from the first test.

Spent a couple of hours tracing wires and removing/replacing fuses, removed the OnStar fuse as well, to see if there were any differences but alas, I did not find any thing that stuck out and said here I am. Anyone have any recommendations for troubleshooting an electrical issue like this with minimal equipment? I hate spending the money to go to a dealer and have them figure it out, if they even can.

Thanks!

Chris
 

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2002 chevy trailblazer_ltz
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Here are the ground listed in my service manual. Some you have to look for, others are clearly labeled. These are for the 4.2 and 5.3L engine. I have also included the short and long wheelbase. Be aware that the grounds may have changed from the early to late model years. Was about 20 pages I had to scan.

I hope I can fit them all in this post.

Hmm. It seems one of them got lost across my network. I will add the missing scan later on in the day.

Thanks! Helped me too!
 
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