1994 Jaguar XJS Interior control panel light and cooling fan will not shut off!

Hey Parnell, chances are the fault could lie with the fuses or with the body control module, I don't have a lot of experience with this model Jag so start with the fuses, if memory serves, there are two fuse panels, one under the bonnet and the other above the drivers knees inside the car, check them electrically with a test probe, looking at them is not enough. Replace any that are blown. If they blow again, seek the help of a qualified professional. If the issue is with the body control module, dont mess with it, have it repaired by a qualified professional. Check the lights switch and the interior light switch as well, if they are both on the same control ( interior lights and dash lamp dimmer) check it to ensure it is switching correctly. You may find that the dash lights and the external parking lamps may not be working as they are connected in some models so go the fuses first. If all else fails, try your local library for a copy of the wiring diagram or search it out online, this will tell you what and where the lights are connected and how they are switched. You can then backtrack each circuit to locate the issue. Again, if it looks like the issue is in the body control module, dont mess with it, that technology needs very specialist equipment and training..

These lights are actuated only by connection of the ground wire(white) to the body to complete the circuit. The only place these connections are made is at the door buttons and the rheostat on the dash that dims the dash lights also when knob is turned counter clockwise to dim the dash lights and clockwise to brighten them and on past that bright point to turn on the interior lights. One of the door wires may be bared and close to the body and arcing, making the lights come on and when the wire warms it pulls away from the body and lights go out. You need to remove the kick panel to access this wire and see if it's still plugged onto the back of the button connection and check for bare spots on wire.

That is normal operation, as long as the door is open the door ajar switch senses that and keeps the interior light(s) on.

The fuse panel is located under the driver's side of the dash. I'm not sure off hand which fuse controls these lights.

I had a problem with the air bag light on. The wire in the cancellation module was damaged. I purchased a used one on ebay and that fixed the problem.

Check your owners manual for your fuse panel, it will show you the location of the fuse panel, as well as the fuse location for the interior lamps. If the fuses seem ok, check your door switches, located near your door hinges on each door, they should be spring loaded, and mov in and out freely. It is very likely some dirt,or rust has locked one of the in the closed position, however if all the switches are funtioning properly, Check the interior dimmer switch, this controls your dash light brightness, as well as your interior lights. If you cant control the dash light brightness this is likely the culprit.

have you moved the switch to leave the interior light on all the time?
have a look at this first,,, if its not that then it could be a door switch sticking on you or the light delay turn off device has gone short circuit on you it has whats called a "tryac" its an electrical switch in the light delay circuit that when it go's pop some times failes in the closed poshion leaving the light on for safty,,,
i hope this has helped you

number 8 controls the courtesy lights, but if interior lights stay on check door switches

is yiur batery in your key ok?