Jaguar Repair: window lift motor relay, distributer cap, thermal breakers

Question
I just recently bought my 1985 jaguar xj6.I have changed out fuel tanks,pump,fuel filter,wires,plugs,distributer cap,roter button.When the car has been operating for some time I begin to have a loss of power and rough running.When car cools back down starts right up and runs fine.I am going to replace the ignition coil tommorow as when the car is at normnal operating temp coil is on fire.My problem is that suddenly my power windows and sunroof sre stuck open.I have tested the switches and they work.I see in the wiring diagram thet there is a relay and a thermal swich which I cannot locate.Could you please tell me where these are located and any other relevent help is welcome.Thanks

Answer
Hi Gerald,
The relay in in the upper most right end of the Aux fuse panel and the two thermal breakers are on the far lower right side of that Aux fuse panel. Just follow the trail on the wiring diagram to see where it goes. The relay is powered by direct battery power and the trigger coil in the relay is powered but the Ignition switch. Are you sure the master switch is not turned off on the console?

As far as the coil getting hot, some series III cars had a coil resistor and others didn't but the coil had to match the system. The system that used the resistor used a 6v coil and the system that did not use a resistor used a 12v coil. If you have a 6v coil without a resistor the coil will for sure over heat.

You will run out of money before you fix the car if you keep buying parts for it to fix it. When the car is in it's failed mode that is when you must start testing.

First and easiest is to put a timing light on the coil wire (not a plug wire) and tape the trigger down and place the light under a wiper arm so you can see the flash of the light when driving and at the time the engine fails look at the light. Even a few misfires due to Ignition it will show as flickers in the steady light. If the light stays good all the way to the engine stopping, then it is most likely a fuel problem. If that is the case let me know and I will give you the next series of tests.

Howard