Electric seat switch not working

Xjs v12 electric door reclining seat switch not working any help appreciateed

What year is your car

Xjs v12 facelift 1992

Nick - - forgive me asking, but I have to assume that you ruled out a bad fuse? On my 1995 V12 Coupe the recline motor fuse (#12, 20 amp) is separate from the fore/aft/lumbar fuse (#1, 15 amp). I don’t know that there is any fusing changes between 92 and 95 so I assume they are the same. I am not good with electronics, but the below is what I would try (unless someone else chimes in with better advice) :

If the fuse is good, I would try to check the switch. Electrical schematic (again, mine says XJS V12 1995 Electrical Guide) shows there is a 13-way Sumitomo block connector (red) Driver’s Door Harness connector at the left A post. (Would keep you from having to pull door trim) WIres from the switch which you would be concerned with should be Orange and Orange/Red. Stays Orange and Orange /Red all the way to the Driver Seat and Mirror Control Module under the carpet in front of the seat. You should be able to use multimeter between a ground point and the pins of the connectors and see if you get 12 volts on the Orange or the Orange/Red wire pin out of the harness when you push the door switch in either direction. The switch is on battery power. If you don’t get voltage you probably have a bad switch or it has developed a poor connection - - then you can worry about pulling door panel and trim, and then fuss with the switch.

If the switch is good, then is the motor getting power? 12V outputs from the Driver Seat and Mirror Control Module are carried on Slate and Slate/Brown. You could disconnect the Recline motor harness (6-way multilock beneath driver seat) from the Driver Seat and Mirror Control Module and then jumper 12 v to the motor to ensure it moves - - if so good motor. Only other things then become the control module or possible the potentiometer that controls how far the motor will move (recline) the seat back

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Great info Jim! Maybe I’ll look into mine this weekend too!

i hope it is good. Haven’t done it - - just seems like a valid approach. As I said, electrical is way over my head.
Since I am such an electrical dummy, I would isolating the control module out of my connections before trying to apply 12v to the seat recline motor. I am always afraid I might fry something and have to replace a control module because of my sloppy work. A concern also might be ensuring a sturdy enough wire gauge for the up to 20 amp voltage to the motor.

I know there are some guys on the forum who really know their electrical stuff. Hopefully one of them will impart some wisdom.

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I have checked fuses all good , when I press reclining switch I here a click under dash but back rest not working/ reclining what can I check this is drivers seat
Many thanks

Jim is correct that the facelifts have very complicated electrical diagram. In addition to the above suggestion to check fuse #1 and #12 in the left component panel, one should also check fuse #14 for the mirrors/seat memory function. If this is blown, BOTH seats and mirrors won’t work…

BTW, 1992 and 1995 have very similar electric diagrams (Fig.15/16, only the former attached)

Have checked all and still not able to fix recline seat

Any further suggestions appreciated

Nick - - was this a seat recline function that WAS working? Or is this a new project car and you are trying to resolve a newly discovered problem? If it was working and now isn’t, and you eliminated all the things discussed above then I have only two ideas left.

  1. If the motor works when jumpered with power, perhaps it is being “travel limited”. Maybe when seat assembled last time the seat back position was at an extreme and corresponded with it being limited? I am talking out my hip region, but just speculating …

  2. Could it be a break in the wiring or bad capacitor on motor?