Brett Jenkins

Driver's side door won't lock/unlock with central lock button or viper alarm fob. Checked power between brown wire and red wire at door lock motor, nothing.

Checked fuses behind CE panel, both ok. Checked power between red/white side of fuse holder and red/blue side and nothing. Same check on passenger side fuse holder shows ~9v. Checked between red/blue wire from driver's side and red/white wire from passenger side, ~9v. Checked between red/white wire from driver's side to red/blue wire from passenger side, nothing. So, the red/white wire at the fuse holder for the driver's side seems to be the culprit.

I am quite electrically challenged, so any thoughts on this issue would be greatly appreciated.

Bill Ball

Hi Brett:

You and I are about at the same level electrically, so this should be fun. Alan will see this soon enough and set us straight. Anyway, it looks to me like you may identified that there may be no power to the driver side lock motor fuse. This originates from plug A25 (plug A, top of second column). So, it would appear there is a break in the red/blue wire between the fuse and A25. Have you checked for continuity? Or you could test the voltage of red/blue side of that fuse versus ground. It should be 12V or close to it. If there is no continuity or power you could put in a jump wire from that side of the fuse to A25. Some of your testing from driver to passenger side doesn't make a whole lot of sense to me. Lack of power to the driver side fuse would explain the failure. Look at that. I wasn't aware that these were fused outside the CE panel until I looked at the wiring diagrams after I saw your post. It's completely different in my 89.

Brett Jenkins

Here's why I was attributing it to the red/white wire from the driver's side.

A = red/white driver side
B = red/blue driver side
C = Red/white passenger side
D = red/blue passenger side

A + B = nothing
C + D = ~9v
A + D = nothing
B + C = ~9v

So A seems to be the common factor in the tests that get nothing and A = red/white driver's side.

Why is there a separate fuse for driver side and passenger side? I wonder if I could just splice in the red/white on the driver side to red/white on the passenger side.

Bill Ball

Hmmm... Yeah, I'm not sure why they are fused separately. Later on they are not.

So, I can see how you are suspecting a break in the red/white wire and not a power problem. I get that now. The only problem is you don't know where the break is, so your jumper would have to go all the way to the motor. And it doesn't matter if you jump from the driver fuse, which you have shown is getting power, or the passenger fuse, other than you would be potentially overloading the passenger fuse if you double up on that.

I would have just done direct testing of the driver side. Look for power on both sides of the fuse versus ground. Then look for continuity of the red white wire from the fuse to the motor. Then I would check the two segments on either side of T3. Then verify ground continuity of the brown wire at the motor. The most common break point is in the harness where it passes into the door, due to flexing when the door is opened and closed. I had a failure of the mirror adjustment in one direction. I figured out which wire it must be, cut open the harness at a tight flexure point, cut off some insulation of that wire and, lo and behold, there was the break which I fixed.

We'll assume the lock/unlock signal wires are working as it would be unlikely for both to fail. However, the motor could be dead.

Brett Jenkins

Well, the 2 fuses looked ok visually, but when I put it back together to trace the wiring close to the door, I must have swapped the fuses because the passenger door stopped working until I swapped fuses. So, evidently one fuse IS bad. I put the good fuse in the driver's side, but the motor wouldn't work, even though I have 12v at the connector now. If I remove the motor from the housing, I can get it to spin the wheels if I fiddle with the contacts inside with power applied, so I need to search for some info on repairing a door lock motor now, since they are expensive.

Brett Jenkins

Can a door lock motor from the right side, be refitted to the left side, not the whole assembly, just the motor itself? I have found one on ebay, but it's right side and my left side motor is kaput.

MainePorsche

Brett,
I had Driver door open/close mechanically normal with key. This would not however lock/unlock the R door motor as it should. The Driver door motor would operate normally off the central button and R door locking/unlocking.
I found no battery voltage at the red and brown leads at the Driver motor 4 prong pig tail. No Voltages from brown to either yellow or green at pigtail when locked/unlocked. Dissected Driver door harness at stress point and found 3 wires severed, one of which was the BROWN to motor. Repaired and now all functions as intended. I had a recent post regarding this. I would look at the wires at the door flex point before hunting/tracking a new motor.

Edit: I had already checked the fuses behind the Board and they were OK.
See page 57-15(25?) in WSM for troubleshooting the motor.

Brett Jenkins

I have already checked fuses and wiring and fixed any issues and have power to the door lock motor, the motor just doesn't work anymore. So, I'd like to just replaced it but they are $$$$ new.