[Aeroplay]

All of a sudden, a few mornings ago, my trunk wouldn't open. I have tried both the button on the key fob and the one on the door. For now I've had to resort to using a rope on the emergency handle through the armrest opening. My first thought was that the wiring had frayed again, since I've had that issue before, but I parked indoors a couple days ago and found that that was not the issue. With my trunk open, I used my digital multimeter to test that the voltage was getting to the lock when my trunk button on the key fob was pushed, and everything seemed fine. Just in case something was shaking loose on connector H10-2 when I closed the trunk, I checked the connectors a few more times and put ox-gaurd in the contacts to ensure contact. Everything seemed to work when I was testing with the trunk open.

The mystery that I'm trying to figure out is why the lock doesn't work when I want to open the trunk, but if the trunk is open, it does. I would rotate the latch to the locked position and then hit the unlock button on the key fob or the door, and it would actuate and unlock. But as soon as I closed the trunk and tried the same button...nothing. There was no sound of attempting to actuate... all it produced was repeated frustration.

The only thing I can think of that would cause it to work intermittently like this is that something is causing the system to short when the trunk is closed, but I can't figure out what would change when closed and create a short. Whether it's a short or not, does anyone have ideas about what could be causing this unusual behavior?

 

[unclemiltie]

Wiring harness connecting trunk lid to the body. Drivers side, by the hinge.

known "failure" mode. Crawl into trunk, open from inside (may have to take the liner off depending on year) and then take the harness out and repair. The break will likely be right where it enters the trunk lid.

Search the forum, there are quite a number of posts on how to do this

 

[Aeroplay]

Frayed wires would have been the simple answer. It was the first thing I checked when the problem started a few days ago. There is no fraying and the actuation of the lock works perfectly when the trunk is open. Other ideas?

 

[unclemiltie]

Still 99% chance that the wires are bad. The issue is not "frayed" wires but "broken" wires, and those breaks can be inside the vinyl insulation and you can't see them

The statement that it works perfect when opened even makes my suspicion stronger, in that the wires are flexed in a different direction and the connection is made.

 

[mecgmecg]

Still 99% chance that the wires are bad. The issue is not "frayed" wires but "broken" wires, and those breaks can be inside the vinyl insulation and you can't see them

The statement that it works perfect when opened even makes my suspicion stronger, in that the wires are flexed in a different direction and the connection is made.

+1 for this statement. The wire is probably pulling apart with the trunk lid down, and touching enough to work when the lid is open.

 

[Aeroplay]

I'm going to troubleshoot this some more after work and see where I'm losing the signal when the trunk is closed. Broken wires would be an easy fix, but I would be disappointed with how fast my new wires from summer 2011 broke. Last time I fixed the wires I took the time to splice in all new wires and I put in a spare for a future break, which would come in handy if that is actually the cause now.

 

[Aeroplay]

Now I feel embarrassed a little, the wire had broken in the usual spot. When I checked earlier this week I didn't move the wires far enough to see the spot where it had chaffed and broke. All of the wires were wearing through and one had broken. I used the spare wire and patched up the rest. I was really hoping this problem would go away after putting the time in to replace all of the wires last time around. Maybe i should just put this on my calendar to check every year...