Hi: I'm considering buying an '86 xj6. It looks real nice. There are some electrical gremlins like none of the windows go down or up and when you toggle between fuel tanks, the gas gauge only shows a reading from one tank and zero from the other. Are these deal killers? Other than that it drives good. Thanks, Ren

 

First, if all the windows are inoperative the likelihood is that the lock switch for the windows (on the same console panel as the window switches) has been used. If the problem is in the 4 individual switches (which you can test by simply trying the 2 switches on the rear of the console) then the switches need to be taken apart and cleaned. They carry full voltage so the contacts do become carboned and need cleaning every decade or so (!). But if none of the 4 windows operate from the console switches it will almost certainly be the simple lockout switch having been used.
The fuel selector switch: assuming that the system has not been altered, the switch readings are controlled by the level sensor assembly and by the function of solenoids - the tank switchover solenoid on the floor of the trunk, and the fuel return solenoids (in the exterior rear wheel wells) - all of which are easily dealt with. If you get a zero reading on one tank, the first possibility is that there is no fuel in that tank (!) ....and that suggests that there is a malfunction of the return solenoid, or that because of a leak/corrosion, the owner has not used that tank OR that the fuel level sensor is bad or its contacts need cleaning (accessed by removing the rear tailamp assembly.
None of the above represents a major issue on these cars - these are very repairable cars.

 

yes, the "Lock" or "Valet" switch is the one in the center-top of the "Ski Slope" where 6 switches are located.

the center-bottom switch is for the Sunroof.

the two switches at the rear of the center console are for the rear seat passengers to operate the rear windows.

the "Lock" switch turns power OFF to ALL the window switches and to the Sunroof switch. Total of 8 switches counting the 2 at the rear..

when testing the window and sunroof switches, try to do it when the seller is not looking, so you can use that as a price-negotiating point. "the windows don't work, that's a costly repair".

**Note that the Ignition Key must be in the ACC or ON position for most electricals to work.

**the glove compartment light only comes ON when the Headlights switch is in any of its ON positions.

**the FOG lamps position at the Headlights switch came disabled in USA cars. To enable the FOG lamps switch position, the switch KNOB must be pulled off the switch SHAFT, and a "C" clip located over the switch shaft must be removed. (This is in case you want to install Fog or Driving lamps under the front bumper).

**Standard Jaguar lights design dictates that when the FOG lamps are turned ON, the HEADLIGHTS are automatically turned OFF.
This design is like that since the 1950's.

**the wiring to install FOG lamps is already there in the car. Two Red wires with Yellow stripes are located at the front passenger side in front of the radiator. They are covered with black electrical tape. All that is needed is two lamps and mounting bolts and brackets.

Good luck!