k, so this same 1991 940SE wagon ('965' on the vin plate, serial # in the 002000's) I'm sorting out for my kid (see various other posts)

last thing I haven't gotten around to... the power door locks. this car does NOT apparently have the alarm system or remote, the driver's door has a purely manual lock, while the other doors have electric locks.

if I lock or unlock the drivers door with the key or with the post, the tailgate locks/unlocks reliably, the front passenger door sometimes locks/unlocks, and the rear passenger doors never do. all locks work fine manually. each time I push up or down on the lock post, I hear a BRRRR (about 1-2 seconds long) coming from somewhere that I haven't yet isolated, might be the back doors?

am I likely to A) need a new lock relay, or B) have to troubleshoot lock wiring or C) replace one or more lock motors?

where *is* the relay panel on this car? it has the fuses on the far left end of the dash facing the drivers door, not under the dash like some others. my VADIS seems to think they are in the center console behind the coin and ash trays?

 

ok, I've found the relay panel and identified the lock relay ("C" on the early style 960 panel)... since the relay is cheaper than the lock motors, I figured I'd swap it first. $#@$#@ dealer got the wrong part on a special order, so we're waiting for the right one.

I've tried disconnecting all the door lock motors except one at a time, any one I connect goes BZZZ for 1 second but doesn't move. I do see + or - juice across the connector to a given lock motor, but I don't have an oscilloscope or whatever so I can't see if its clean DC or some kinda AC-ish stuff which would explain the buzz. even with all 3 doors disconnected, the tailgate lock buzzes too (and on other 940's I've tried, they don't buzz, just klunk).

 

finally got the right relay Wednesday, and nope, didn't fix it. :-/ same symptoms. ran out of time, not going to be able to fix until car + son returns from college next spring.