THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

Spot on, Jose. The nut is part of the switch body and came right out with a 1/2" socket. I cleaned all the surfaces and voila, interior lights again on door opening. The first photo is the door switch, the second the interior of that interior/panel switch.

awiedie wrote: ↑Wed Feb 20, 2019 5:30 pm Forget that last comment about pulling the circlip to remove the resistor, I can see now that the resistor appears to be held down with the terminal screws. There is a part number in the Lucas electrics book for the resistor, however - 54334020. Probably never find one though.

Now that I have located my front door plunge switch, I find that there must be a bad ground at the switch because the light now comes on but sometimes bright and sometimes dim and sometimes not at all. The switch/ wire connection is not accessible from inside the car. If you removed the nut at the plunger, could you withdraw the wire and switch back through the grommet hole in the side panel?

Alan ~ I doubt that you will find a genuine 54334020 but I'm sure Radio Shack or some electronics store can provide you with a suitable resistor.
The switch should retract & bring the wire & bullet connector with it. Harness access requires you remove the kick panel.

Give them a good spray with CRC Switch cleaner. It's the right stuff!

EDIT: Sorry ~ we all posted over one another.

awiedie wrote: ↑Wed Feb 20, 2019 9:41 pm Spot on, Jose. The nut is part of the switch body and came right out with a 1/2" socket. I cleaned all the surfaces and voila, interior lights again on door opening. The first photo is the door switch, the second the interior of that interior/panel switch.S Type switches 002.JPGS Type switches 001.JPG

excellent Alan. Glad you nailed that problem. Both of the switches look clean, unrusted.

What is part number 7 in the plate below? Is it an Instruments Voltage Regulator? Does it have anything to do with the panel lights? I am wondering if that is the problem, not the lights switch.

It is a voltage stabaliser. It's stops panel lights etc dimming & brightening at different charge rates from the Dynamo & ensures constant voltage to the instruments etc.

that might be the problem, not the resistor.

Looks to me the "resistor" shown in the headlights switch is more like a "JUMPER" from one terminal to another.

that voltage stabilizer should be tested, it could be causing the problem with Alan's panel lights.

No it's not the problem. If the voltage stabaliser was blown none of the instruments would work apart from the ammeter which is direct wired & the Speedo which is mechanical. None of the panel lights would work either. While old technology the voltage stabaliser tries to see that the instruments etc. see a constant 12 volts. The charging circuit operates from discharge to an approx cut out of 14.2 volts by the regulator. The instruments etc. do not want to see that sort of voltage fluctuation. e.g. without the voltage stabaliser the fuel gauge reading would vary with the charging rate.

The resistor achieves the voltage drop to dim the warning lights when the sidelights etc are switched on. See the wiring diagram.

Here is another example of using a voltage dropper resistor to dim the heated rear window indicator light when the sidelights are activated at night.

The circuit for the heated rear window switch & indicator light. As this was a later fitment Jaguar included a 6RA Relay & dropper resistor for the sole purpose of dimming the warning light at night so as to match the rest of the car.

If you have checked all connections & established that no indicator/warning light with sidelights burning is as a result of a failed resistor. The replacement resistor value should be 47 Ohms 10% tolerance & a minimum rating of half a watt.