Hello:
I have a 1985 XJ-S with the six cylinder motor and a five speed. I have recently had a problem with the windshield gasket leaking. One day I noticed none of my instruments were working. I have checked various fuses and I have even pulled the cluster out and reseated the two large wiring connectors on the back of the cluster assembly. The lights in the instruments work and the warning lights work but none of the instruments work at all.

Any suggestions? Are there any hidden fuses that are not located in the regular fuse panels under the dash on each side?
--
Steve

 

I have checked fuse # 4 in ther left hand fuse box and it does have power on both sides of the fuse when the key is on but I have also discovered that I have no reverse lights which I believe is something else that is powered from this same fuse. Investigation continues.

 

I have the same issues. Rain leaks in through the windshield. The instruments are currently working, whenever rain got into it they stopped, try letting the car dry as much as possible, avoiding rain. As long as mines is dry, the instruments work fine. Hopefully this helps.

 

All instruments out should mean either a fuse or just as likely a fault on the earth side of the instrument binnacle. If you have a reasonably sensitive meter, then with the binnacle out and the multiplug free, you could test some of the instrument feeds to see if any signal is coming in.
I am searching for a diagram I have somewhere saying what each little copper contact on the plug feeds, but so far no luck. If you trace back the copper contact line on the blue flexible circuit "board" from (eg) the fuel gauge to the point where the plug contacts the "board" you can identify the feed contact on the plug and test it.
All the instruments earth via into one earth on the "board" so the earth sides are easy to find and distinguish from the feed side of the circuit board.
Greg

 

I found a diagram of the connections on the plugs on the back of the instrument binnacle. It is supposed to have power coming into pin 10 of the 12 pin horizontal plug (versus the 18 pin vertical plug). Pin 10 is on the bottom of the plug right next to the one missing terminal on the plug to the inside of the missing pin.

I have confirmed that I have no power here. I have rechecked the power at the number 4 fuse and I do have power on BOTH sides of that fuse but it never gets to the instruments, the reverse lights or the trip computer.

Is there some connector between the back of the fuse block and the power feed to the instruments, reverse lights or trip computer?

Any and all suggestions are MOST welcome here. One of my other cars I have been driving has developed a different mechanical problem so I need to get the XJS operational again by getting the instruments to work.

 

Nevermind, I was looking at the wrong end of the fuse block when I was counting to fuse four. It turns out the instrument & reverse lights and trip computer fuse is blown. When I put a new fuse in and turn on the key, it blows again right away so I have some dead short in the circuit.

I tried removing the trip computer from the car, replaced the fuse and tried again. Still no luck as it blows the fuse again as soon as I turn the key on.

Next I removed the instrument binnacle from the car, replaced the fuse, turned the key on and the fuse again blew right away. So it's not the actual trip computer or the actual instrument binnacle. Next I am going to try somehow disconnecting the reverse light part of the circuit.

 

Does the bulb failure light stay on when you switch the lights on?
It sounds like it could be a corrosive short in the reversing lights; I have the same on the left side reversing light on mine but it doesn't blow the fuse.