door lock/unlock switch not working

[rsottawa]

Hi All,

08 coupe, noticed today that the lock/unlock door panel switch (both doors!!!) does not respond, no clicks nothing. Weird thing is that all other methods for locking/unlocking doors works (i.e manually, nissan remote, door handle).

Any ideas what it could be?

Thanks.

[InfinitiEric]

Could either be an electrical issue with the fuse that handles the switches or a mechanical issue with the locking mechanisms. You're going to have to some backwards investigation or go to a Nissan dealer.

[rsottawa]

Is there a fuse specifically for the door lock swiches. I checked all the fuses inside the car and all are ok.

[InfinitiEric]

There isn't one specifically for the switches, the fuse would handle more than just the door switch components. But if they're all showing as okay then it's a problem with the mechanism not electrical.

[wade001]

i dont think its mechanical, if it was the actual locks they wouldnt work no matter what. i think its a electrical issue with the circuit from the switch. was this out of the blue or intermittent at first?

[rsottawa]

It was out of the blue, just happended to notice that the doors were unlocked when I was walking up to the car the other day.

I also tried unplugging the battery for 20 mins but no change.

[InfinitiEric]

It's not electrical… mechanical problem with the locking mechanism. It's a known problem on the G37 I believe.. Search >>

[wade001]

if your not experienced with electronics i suggest taking it to a professional. it could be a lot things as a source to the problem (not excluding mechanical). but toy with it if ur up to it -_^, just be careful..

[rsottawa]

Update:
I have confirmed that the problem is not mechanical in nature. I also tested another master door switch and the problem remains.

I took the Clifford alarm out, I believe a relay (for clutch kill) has been sending a positive (+) signal to the grey and grey/red wires (signal wire for lock/unlock) instead of negative (-) and this has damaged the circuit in the bcm that controls the lock/unlock switch. This relay was recently installed to replace one that had died (was not diode protected).

Now here is the weird thing. Seeing as I'm pretty sure I'm in for a new bcm, I thought I'd see what would happen if I applied positive (+) to the grey and grey/red wires momentarily. When I did this the locks locked and unlocked! When + was applied to either of the wires the door switches started working again as well but only while + was being applied. I only did this as a test and did not leave it wired to +.

So it appears that my door swiches have somehow switched polarity, posivite(+) door locks instead of negative (-), bizarre...
Any constructive thoughts would be appreciated.

[InfinitiEric]

Well nobody mentioned that they had an aftermarket alarm on,