bertboy80

I have a 04 a4 Quattro with the 1.8T. Over the last few months the electric trunk latch would sometimes not work. Now it has completely stopped working. I've removed the trunk lid liner and am trying to troubleshoot the problem. The switches on the lock cylinder and latch seem to be working and when I push the release button on the trunk lid it seems to be sending voltage to the latch motor, but the latch motor doesn't move or make noise. I took the latch motor out and bench tested it. Hooking it directly to the battery makes it run, but if I use the 11.5 volts coming in on the hot wire in the trunk, the motor won't run. I did a continuity test on the motor and there is no resistance.

So can anyone tell me what the problem is? Is the motor nearly shot and so it only moves when 13 volts are applied instead of 11.5?? It doesn't seem to make sense...

Thanks,
Robert

lyleswk

So if I understand, when you attempt to open the trunk from the driver's door, it doesn't open. But when you push the button on the trunk itself, it opens? Or, neither opens the trunk?

bertboy80

No, neither button opens the trunk, it can only be opened with the key. Is there a control module somewhere or does the circuit only include the drivers door button and the switches and button on the trunk lid?

thanks

lyleswk

Sounds similar to a problem I have then; mine is still intermittent. I would suspect that electrically, there is probably a short in the door jamb harness that is shorting out the whole system, but have yet to prove that.

bertboy80

I got my problem fixed! I continued troubleshooting and finally discovered that if I created a new ground right on the trunk lid, both buttons would function properly. Apparrently there is either a bad ground in the system somewhere or the ground wire that runs back to the trunk lid is broken somewhere. I simply spliced a wire unto the ground wires and grounded it on the latch stud and everything works normally.

My problem had started intermittently too, so I wonder if your problem, lyleswk, might not be that same as mine.

Thanks for the help!

lyleswk

Thanks for the feedback. I may try that as well. Can you describe a little more what you did? Are the ground wires obviously marked (black?). You just backed the latch stud off, put the wire underneath, and then retorqued the stud?