My 91 XJS V12 convertible mirrors both stopped working. It's not the fuse, as it's shared on the panel with (Working) door lock system. The switch is readily available from many sources. Is it easily swapped out, or is the door card have to be removed? Lastly, could a good cleaning of the switch contacts possibly resurrect it?

 

Anglico
The mirror adjustment loom connectors are rubbish. Those tiny connectors easily corrode and easily fail to make contact. You will need to test the system right through to find the fault. On a pre facelift anyway, you can unscrew the two retaining screws of the switch surround and carefully ease out the switches and surround as one piece. There should, repeat should, be enough loom for you to get at the connectors, if not then the door car has to be removed. One two-pin connector brings in the 12 volts, test to see if it is carrying current. If it is, then clean up the connector pins on all the plugs, then plug in the current carrying connector to the switch loom, and then test the other two 4 pin plugs for 12 volt output, as you move the switch in each of the four directions. The current should be live on each of the four plug pins, depending upon whether the switch is pushed N, E, S or W. If no current coming out, the switch is duff. If it does, then reconnect the system and see if the mirrors move; sometimes they move in only one orientation, for example. As long as the switch pins get current, if the mirrors do not move, next step is the mirrors themselves.
The mirrors can be unscrewed from the outside; again carefully pull the mirror away and you should e able to get at the connectors but string them so if they fall back into the door you can pull them out again! Same job, clean them up, and then test the pins for current while a friend works the switches. If you are getting current, reconnect the mirrors and see if they work, or at least in which direction they work. Finally, if the current is good to the mirror connector, but the mirror does not work in one or both directions, the mirror motor may be duff, or may need a squirt of 12 volts direct to the mirror plug from a battery to get it moving.
Second hand switches are available, obviously, but they may or may not work, so test them as described above, and return them if they do not. New switches are NLA.

 

Great information! Where both mirrors stopped at the same time, I believe the fault must be at the switch end, and not the mirror motors. Are the two switches separate, or do they share a common power connection and/or ground wire lead?

 

 

Those connectors should have cable ties around them to stop them fall apart, if the cable ties are missing or broken you may have lost the incoming power to the switch. This would cause both mirrors to stop working at the same time.