Hi guys,


I have new window switches coming but was curious if there is a window fuse or relay and where it is located? Both windows were working until I installed the new ski slope and I am thinking I messed with the wiring or may have blown a fuse/relay. Thanks...

 

You have a relay and a circuit breaker, both behind/below the glove box.....or at least where I've always found 'em

The circuit breaker is roughly 1.25" square, two wires....most likely white/pink and brown/blue. You can bridge the terminals with a jumper wire, or join the two wires together, and see if anything changes. Or use a test light or meter to check for voltage in/out

The relay is on the component panel below the glove box. Probably with brown/blue, black, and white/pink wires. Black is ground. Brown/blue is contat 12v. White/pink is 12v with key "on"

I say 'probably' because I'm working off a 1989 diagram at the moment....but your 1990 is 'probably' the same.

Cheers
DD

 

Thanks Doug. I'm hoping the new window switches work because I'm not really knowledgeable working with electronics/wiring. I can handle mechanical things but have always tried to stay away from car electronics. LOL... I can replace a fuse but that's about it. Thanks for your help.

 

With a 12 volt test light ($10.00) and a little bit of coaching (provided by any number of the members here) you can be well on your way to diagnosing many common electrical problems....such as power window circuits.

In-depth knowledge of electricity isn't required to become a pretty decent DIY electrics fixer

If you decide to get your feet wet just give a shout. Many here will help.

Cheers
DD

 

Installed the new switches in my 90 XJS and they did not work. Nuts... I removed the screws and lowered the lower passenger side dash and found the area with 4 relays. Any idea which one is the window relay? I think I saw a red, black and I if I recall, a yellow one. I'll have to take another look tonight. I do know the windows did work before I removed the old switches. It has to be the relay, right? I wish I knew more about electrical stuff. Thanks guys.

 

I can't remember the exact location of the relay but the wire colrs mentioned above will probably help.

An easy first step would be to locate the circuit breaker and jump the terminals. Or remove the wires and touch the wire ends together....and then try the windows.

Cheers
DD

 

[QUOTE=Doug;951148]I can't remember the exact location of the relay but the wire colrs mentioned above will probably help.

An easy first step would be to locate the circuit breaker and jump the terminals. Or remove the wires and touch the wire ends together....and then try the windows.

Cheers
DD[/QUOTE

I wish I knew what the circuit breaker looked like or where it may be. I'll see if I can track down the wires mentioned above and try go to a parts store and match up a circuit breaker and relay. Thanks Doug. Wish I was better at this stuff. At least the car runs like a dream. I should have left the original ski slope in. Lol. Nuts.

 

Item #6 in the drawing

Part no. C44001 | Window lift thermal cut-out switch parts from Jaguar Classic Parts UK


Cheers
DD

 

Thanks Doug. I'll remove it and check and see if I can find a replacement. Can I remove the two wires and connect them to see if the windows work? I just don't want to blow anything else by doing this. LOL.

 

Doug is right, buy a test light and we can guide you through the process, it is really quite simple.

My first suggestion is to check that you have correctly installed/wired the switches and have power to them with the ignition on (Pos I).

If you do not have 12v (test light does not come on) then the thermal breakers or the wiring from the breakers would be the suspects.

You would then check to see if you have 12v on the input side or both input and output side of the breaker. You should see 12v on both sides. If you only have 12v on one side then your breaker is bad. If you do have 12v on both sides then the issue is with the wiring from the breaker to the switches.

Here is a picture of the breaker. SWITCH-CUT OUT - Terrys Jaguar Parts - DAC11334

 

The relay controls the feed for both the window switches and cigar lighter, so if your cigar lighter works the relay is ok but if not, it would be my primary suspect (although there is a separate fuse for the lighter)

 

See post #6 above.

Nothing bad will happen *unless* you have a dead short. Unlikely in this, IMHO, but possible. Then you'll get smoke.

Here's an alternative that will make you more comfortable:

Unplug the wires from the circuit breaker and attach them to a 20 or 30-amp fuse. The wires will slide right onto the fuse. Your fuse box might have some spare fuses, or you can just buy a packet.

If the fuse blows then you have a dead short. If the fuse does not blow and then windows now work then you know the circuit breaker was blown....possibly becasue you momentarily shorted the wires during your previous work.

If the fuse doesn't blow but the windows don't work, we can dig deeper into the problem

Cheers
DD

 

Thanks guys, I will see if I can work on it later today. I do have a Actron trouble shooter and it says I can check ac voltage with it. This will work, right? Thanks.

 

'AC' is alternating current.....like what you have in your house.

Your Jaguar electrics are 'DC'...direct current.

Does your tester have a DC setting?

Cheers
DD

 

I do have extra 30 amp fuses and will try that. The actron does also check DC. Thank you...

 

If I use a fuse and it blows and the windows then work, then I need a new relay, right? Why would the windows work if the fuse blows? I would think if the fuse is blown then the window would not work. Sorry about being stupid with this stuff. LOL.

 

Before you do all that, just follow my suggestions in post #10. If you are unsure about causing harm, it is always best to test in a non-destructive way. This will isolate your problem for sure

It takes quite a bit to blow those breakers, my guess is that you have pinched or broken a wire between the breaker and the switches when you removed the ski slope. In which case putting a fuse in place will not prove anything.

 

My fault. Not yours. I edited my earlier post to make sense.

Cheers
DD

 

And, yes, since you do have a meter, simply check for voltage in-and-out of the breaker as Allan mentioned!

Cheers
DD

 

Will do... Thanks guys.