Xj40 drivers seat switch

I have issues with the switches for seat adjustment on drivers side. Are these switches prone to fail or is it more likely that contacts are dirty. 1993 Daimler.

Keith. I believe the switches have a history of reliability.

Keith …

If all the positions (Fwd-Back, tilt, etc) are inoperative then it’s certainly the switch. However if it’s just one then it could still be the switch but more likely the motor in the seat.

What exactly is the problem.

Hi thanks for reply. Some positions operate ie the back of seat is OK but the fore and aft adjustment is not. To move seat back I use the door control and forward movement is achieved by using seat switch. Height adjustment not operating at all.

Keith …

On my '89 XJ40 there is just one screw in the front of the bottom seat squab that holds it on, so very easy to get to the seat motors.

My guess is the electric motors are the problem. Is there a difference if you run the seats with the engine off (on the battery) and with the engine running (power coming from the alternator).

Troubleshooting … Remove the bottom seat squab and determine which motors run each seat function. Find the 2 wires (+ and -) going to that motor and using pins pierce the wires and use a multimeter see if you are reading 12 volts while operating the seat control. This will tell you if it’s the motor or the switch that’s the problem.

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I had one of my switches short out and blow the fuse whenever it was used. The switch mechanisms inside the switch-pack are replaceable from Jaycar for about $4 each.

Thanks that is useful information re jaycar.

Keith, the power seat (and memory) functions are controlled by the ECM (electronic control module) located beneath the panel on the floor immediately in front of the seat. Armed with the wiring schematic you can disconnect the 20 way connector from the ECM and with a multimeter monitor the appropriate wires as you exercise the switches to test them. You can also apply 12 volts to the appropriate wires to test/exercise the individual seat motors (fore/aft, front of seat cushion up/down, rear of seat up/down, headrest). It has been many years ago but IIRC I used RCA (‘stereo’) cables to power the motors when my ECM fried.

Thank you. More very useful information which is appreciated. Will have a play around in the weekend.