Series 3 dash lights not working. New member

New member and new Jaguar owner. Australia, Queensland.
Have a 1984 XJ6 Series 111 Vanden Plas.
Not bad on the spanners but I have a lot to lean with this power system.
The Dash / Instrument lights has stopper working and I have a Bulb fail light on the dash.
Also the Rear Window heat switch is no longer showing a light on the dash. I think it was showing a lit indicator light previously.
I have checked the fuse’s on both sides and all seem to be ok.
Am I looking for a relay / power fault?
The next question is can the Hazard light switch be rewired to a standard switch and if so how do I wire it up.
Looking at getting a new switch but it may take awhile to source one. These small problems are holding me up on getting the car back on the road.
Any help and advice will be greatly appreciated.

Hi Michael and congratulations. I used to have a 84 too although not a VdP!

First, you need to google BS-AU7 which is the standard wiring code. There’s a S-57 wiring guide that is rarely helpful but I think it contains the wiring diagrams.

Bulb Failure light: does it not go off after driving off? Then you need to investigate the bulb failure units, one might be stuck.

For the dash lights, the dimmer aka rheostat is the prime culprit. Then, grounds. It’s always grounds with these cars.

For the rear window heater, I‘d be inclined to pull the instrument. It’s a bayonet and twists out in one direction, I think clockwise for RHD. No tach drive, it’s all electronic. Not sure if the bulb was special.

The hazard switch has broken off? That’s normal, it’s not the greatest design as you probably found out. Replacements are available but not that cheap. A different switch must work the same way otherwise you lose the normal indicators too, besides, you will have to modify stuff and then it’s easier to just pay the money.


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Thanks for your reply.
I have the S-57 drawings and still working my way through it.
I will look at the BS-AU7.
The car had been sitting since 2013 and I have got it up and running fairly well now.
Full new front suspension and brakes. Rear brakes and bushes. Fuel tanks and system. Radiator and hoses plus vacuum lines etc.
Seems every time I think I am getting close a little electrical problem comes up.
Starting to do my head in.

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Adding to Davis’s sage advise, Scrat; the bulb failure may take some half minute to settle after the lights are turned on. If still on, the first step is of course to check if all the lights are working - the bulb failure light may just do its job?

The instrument lights may be a ground fault; some instruments are mounted on a metal subframe, which is then grounded by a black wire - which may have problem. With the broken hazard switch - if you have working direction indicators; replace it. Do not go for a rewiring, it is not worth while…

The rear window demister is powered from the ignition protection relay, which also powers the windscreen wipers. Just check if there is power at the rear window - it might just be a blown bulb?

xj6 85 Sov Europe (UK/NZ)

JAGDAIM in Melbourne stock the Hazard Switch.
Cheers Bruce