• If you currently own, previously owned or want to own an Avalanche, we welcome you to become a member today. Membership is FREE, register now!

Problem with trailer lights... problem is with truck

gn85

Full Member
Joined
Jun 24, 2006
Messages
1,212
Location
Maryland/ Germany
OK, I've found a problem with my trailer lights.  At first, I suspected the trailer, but now I've found out it's the truck!!

I noticed my Rt. side stop light was constantly lit on my trailer, but NOT on the truck.  The truck was not running and parking lights were off.  The parking lights and Lt. side stop light on the trailer were not lit.  No lights on the truck.

I unplugged my trailer (light went out) and probed the connection on the back of the truck.  I have 12Vs on the Rt. side prong.  No corrosion. No other voltage on any other prong.  Good ground.  I then pulled the fuse in the dashboard side fuseblock.  Upon pulling the fuse, I get no more 12V at the connector. 

I suspect the turn signal switch possibly.  Any other thoughts?

Thanks.
 
There are several fuses in the main block under the hood that are labeled - Trailer Right Turn Signal,  Trailer Left Turn Signal, Trailer parking lights, etc.

If you look in your book, you will see that the center plug is for back up lights and there is a terminal that has constant power.

More than likely, you have a problem inside of your trailer plug which is shorting out and causing the power to go from one circuit to another.

The back of the trailer hitch plug also has a plug that you can access by pulling a couple of retainers out and then unplugging the plug from the receptical.
 
Monte Carlo Man said:
There are several fuses in the main block under the hood that are labeled - Trailer Right Turn Signal,  Trailer Left Turn Signal, Trailer parking lights, etc.
I was trying to find that in the resource area (owner manual) but my connection is running SUPER slow and won't load the page I was looking for..  :E:
 
The fuses are in the lower left of the fuse block, check you wiring as much as you can. If you don't see anything it's probably the flasher, it controls the AV turn signal and the trailing turn signal on 2 different circuits PS they ain't cheap about $100.00
 
check under truck ...
there is a harness connector that sometimes get gunked up and causes problems...

might be yours...
 
*** UPDATE ***

Well, I did some digging and sure enough it was the flasher module that had failed.  I went to the dealership and they wanted $97 and would have to order it.   :eek:

I saw that Rockauto had one too, but they had a 12 day wait.  So, in my many travels yesterday, I was near the junkyard.  I've NEVER seen an Av in the boneyard, but from what I read, there were plenty other vehicles that use this flasher module (Trailblazer, Silverado, Tahoe, etc).  So, I decided to go for a walk in the rain.  Figured it couldn't hurt.  Although it must have looked funny with me looking this info up on my iPhone in the middle of the junkyard.

Anyways, to make a long story short. I found a Trailblazer with the same flasher.  Price... $2.  It wasn't the new flasher, but I figured for a $95 savings, it was worth it.  Everything works just fine now.

Many thanks to everyone who posted in this thread and to those who wrote other threads that I searched thru.  Great board!!!
 
Glad ya got her fixed and saved 95 bucks. (y)
 
The only problem is how long will it last, but what the heck you can buy 25 of them and still be ahead. (y)
 
MichiganSilver03 said:
The only problem is how long will it last, but what the heck you can buy 25 of them and still be ahead. (y)

I was driving around with my dashboard apart because I was waiting to get the new part.  After hearing it needed to be ordered and how much GM wanted, I figured it was worth it.

I did pick up a couple of them.
 
Alaska_AV. said:
I love wreaking yards!!!!!!

I really like the bone yard.  Not a lot of stuff I can get for the Av, of course.  But they've been invaluable for my wife's Saturn. 

Using the boneyard is my way of being environmentally friendly.  Not to mention, saving the economy!  The boneyard around here has fixed prices for everything.  I knew that when I went to look for the flasher module.  So, when the guy said $2/each, you can imagine the grin on my face.
 
Glad that you got it fixed.  (y) Good info for future use too.

I would have never thought about the flasher module (thanks MS03).
 
02 Z71 said:
Glad that you got it fixed.  (y) Good info for future use too.

I would have never thought about the flasher module (thanks MS03).

I can't take credit for it, it was the service manual.
 
MichiganSilver03 said:
I can't take credit for it, it was the service manual.

:laugh: :laugh: :laugh:

Are you saying that the service manual actually had some useful troubleshooting information  :eek:  >:D
 
Every once in a while, after you decode what they are saying and go over 3 pages on electrical diagrams. :laugh:

Yeah I have a Helms manual.
 
Back
Top