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2007 chevy trailblazer_ls
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16 Posts
Discussion Starter · #1 ·
I am having problems with my rear tailgate. I have no power to my locks (fob or door switch), rear wiper (or spray) and rear defrost. I have checked the wires that run through the rubber boot from the body and they are ok. I had posted earlier on my door latch trying to actuate only while the tailgat is open but now have lost all function. i am suspicious of the relay in the link below (item #8) but would like to know if anyone has had experince with this and what exactly does that relay control before I purchase it.

appreciate your input

http://www.compnine.com/index.php?u...delid=7155&capuid=1&majorgroup=17&grouptype=B
 

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2009 chevy
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6,431 Posts
You will buy that part, and discover that the only thing you have accomplished is that you have tossed money away on a part that you "probably" did not need.

Why do people think the way to save money is to guess where the problem is and then buy the part.

You need to isolate the problem, trace the voltages and grounds and have the testing pin-point the true problem.

Think about this, you have NO electrics operating on the lift-gate. That is probably not a result of one part failing (it could be, but it is not likely).
However, it could be because something common failed.
What is common, the grounds.
IMO, and diagnosing from this distance, you have a broken ground wire in the wiring bundle.
The grounds are black.
 

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2007 chevy trailblazer_ls
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16 Posts
Discussion Starter · #4 ·
thanks Rayvoy.

Other than the wiring that runs through the rubber grommet between the gate and body is there anywhere else specific to check?
 

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2005 chevy
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6,469 Posts
thanks Rayvoy.

Other than the wiring that runs through the rubber grommet between the gate and body is there anywhere else specific to check?
You're best bet is to trace backwards from the LGM plug that you pulled during the previous troubleshooting before everything stopped working.
 

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Northwest Chapter
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11,824 Posts
You're best bet is to trace backwards from the LGM plug that you pulled during the previous troubleshooting before everything stopped working.
Yep, I unwrapped all the wiring in the liftgate and traced it back to the plug where it enters the truck. Found the ground wire insulation was gone so I fixed it, but still the LGM didnt work. Went through every single fuse in both fuseboxes to make sure none were blown. So bit the bullet and bought one and had the stealer program it, everything works now.

Check all the small stuff first then buy the LGM, I spent a saturday ripping wiring apart and checking fuses before I dropped the $130 for a LGM+programming.
 

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2009 chevy
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6,431 Posts
thanks Rayvoy.

Other than the wiring that runs through the rubber grommet between the gate and body is there anywhere else specific to check?
As Erik suggested in his post, you might have to take the covering off the bundles.
The black wires are easy to find, inspect all of the ground lugs and look for places where the cover might be pinched, or cut, on the black wires.
If all else fails, try moving your fingers along the wires, left and right hands, keep the fingers 2 or 3 inches apart, and gently pull the wire between the fingers.
If a wire is broken inside the insulation, the insulation will stretch when you pull on both sides of the break.
Of course, a multi-meter set on the ohms scale will work as well.

This of course, is one way to eliminate the easy/cheap problem areas.
If the testing does not locate a problem, then, as Erik discovered, the LCM is the culprit.

Good luck :thumbsup:
 
2002 gmc envoy SLT
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8 Posts
I am having problems with my rear tailgate. I have no power to my locks (fob or door switch), rear wiper (or spray) and rear defrost. I have checked the wires that run through the rubber boot from the body and they are ok. I had posted earlier on my door latch trying to actuate only while the tailgat is open but now have lost all function. i am suspicious of the relay in the link below (item #8) but would like to know if anyone has had experince with this and what exactly does that relay control before I purchase it.

appreciate your input

Comprehensive Chevrolet, Saturn, GMC, Hummer, Cadillac, Buick, Oldsmobile, Pontiac, Geo, Dodge, Plymouth, Jeep, Chrysler, Ford, Lincoln, Mercury, Mazda Truck, Mercedes VIN Decoder
This is exactly what was happening with mine and you hear the clicking noise whenever the tailgate is a jar right? So I didn't think it was my wires either but I couldn't figure out what it was and so I took the rubber boot off again and I pulled out the wires like pretty as much as I could from both sides and I found a broken wire and it was a broken ground wire so you should make sure that you're being very thorough sometimes the wires aren't even broken they're just damaged and it does that. Hope this helps
 
2002 gmc envoy SLT
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8 Posts
This is exactly what was happening with mine and you hear the clicking noise whenever the tailgate is a jar right? So I didn't think it was my wires either but I couldn't figure out what it was and so I took the rubber boot off again and I pulled out the wires like pretty as much as I could from both sides and I found a broken wire and it was a broken ground wire so you should make sure that you're being very thorough sometimes the wires aren't even broken they're just damaged and it does that. Hope this helps
I ended up just putting a wire connector on mine and taking off the damaged piece that was almost broken and it went right back to work in correctly everything works the back tailgate locks even with the FOB now and with the door locks so that was my fix it was frustrating for a long time
 
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