Xjs triple faliure

I own a 1990 XJS convertible. Recently I have had an issue with the turn signals, hazard light and brake lights. I will start the car and they all work. I will drive for a while and they all stop working, Then they work again and then they stop, This does not blow any fuses. I had the car in the shop (a British car expert) and they cleaned the Hazard switch. About 25 miles from the shop the above mentioned functions stopped working. I parked the car let it cool down and the turn signals, hazard and brake lights worked. I took the car out yesterday and they stopped working… Parked it in the garage and again they worked. I did notice that the hazard lights don’t function when the ignition is off with no key. I tried to pull the plate that holds the two switches but the left side pins will not come loose and I don’t want to force it. I would test the hazard switch if I can get it out, but can’t remember the procedure. It looks as if all three functions are in one way common to the hazard switch. But the brake lights being involved at the same time is a puzzling issue,
Does anyone have an idea what might be going on??

Well the common denominator between hazards/blinkers/brake lights is fuse #5 in the main fuse panel. Since it’s not the fuse itself, it could be a bad connection across the fuse / there where it connects.

I’d clean the contacts @ the fuse panel & where the connections come in.

~Paul K.

Not a forgone conclusion, quite a few (myself included) have had connectivity issues with the glass fuses not being continuously internally connected.

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With his 90 model, he shouldn’t have glass fuses, but rather spade style fuses. That doesn’t rule out corrosion though. I’d remove and reinstall the fuse several times to clean the contacts. Then, if that doesn’t work, I’d start looking for and cleaning ground points.


Thanks wasn’t sure if that was going to be the case but threw it into the mix just in case.

The hazard switch for the 4 way flashers gets its power from fuse #2, which has constant power. Fuse 5 is switched. As was stated previously, the common thread is fuse 5 which is for the turn signals, brake lights, cruise control. There are several ground points, and I don’t see any commonality there.

Is there any sign of water intrusion or corrosion around the fuse box?


Might insure all the wires are secure as they plug into that fuse box

So two fuses are at issue! matters little, glsss tube or plastic spade I prefer the latter, but of necessity, live with a lot of the latter.

Old tech check. Break out the test lamp. Remove one fuse. plug in the test amp. for a degree of certainty ignition switch on. Operate the hazard switch. Does the test lamp light up? If so, that circuit is good. if not., indcates a path to follow/

Now, if the first is OK, reeat with the other suspect fuse. Lights up? Yes that circit is good. No? follow that path.


Paul and the rest of you who had suggestions about my triple failure,
I took your advice and this morning spent some time cleaning the #2 and #5 fuses and their sockets.
I also went under the hood and cleaned the grounding points that I could find, so far…
So far, the cleaning seems to have done the trick. The turn indicators and brake lights worked on a limited test drive. Before if I stepped on the brakes the turn signals stopped along with the brake lights. During my test, with or without the brakes being applied, the turn signals remained working along with the brake lights. I will take a more extensive drive and let you know.
Many thanks for your help

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