Dashboard gauge/dial lights not working S2

[dontuna]

Hi all. I am sure this has been discussed before and I have searched through all previous posts to try and find solutions. I recently repositioned a gauge light bulb as it had fallen out. I accessed via the side panel on the drivers side. I also removed a redundant immobiliser which linked to the wiring under the steering wheel. It looked as though it should have no impact on the light. Now there are no lights working behind the gauges and dials. Everything else works. Someone mentioned on other chats a switch under the steering column??? I didn't see on. Any photos? I have the dimmer switch above the radio. Could this be faulty? Thanks for any help. This had been a really useful forum. Cheers

[v8s4me]

There is a rotating switch under the steering column which switches the gauge lights on in two positions ie dim and not quite so dim. The switch has an off position so yours might be switched off or there is a wire loose. I suppose you have checked the fuses?

[phillpot]

v8s4me said:

There is a rotating switch under the steering column

Not on an S2 ?

Are all sidelights and number plate light working?

[dontuna]

Thanks for coming back so quickly. Couldn't find any switch under steering column. All lights appear to work other than the rear drivers side light. Other side works though. Checked bulb which is OK but appears no power to bulb. All lights on curved warning console work. Fans and gauges work. Just no back lights on dials! Is it a simple lighting circuit via dimmer switch powered via ignition switch. Can this be easily rewired if fault cannot be found? Cheers

[Peter M]

Hi,
The S2 has a rotary switch on the dash for gauge illumination. I think this is ON, DIM, and OFF. When on DIM there are a pair of resistors in series with the bulbs to drop the voltage. The resistors are mounted in the engine bay on the bulkhead, tucked in the start of the transmission tunnel, I think on the drivers side. The originals on my S2 were white ceramic resistors, but they failed so I replaced with aluminium high power parts.
Check the wiring to these, as this could be your problem.
However the ON setting should still work.

[dontuna]

Thanks. I have checked again and the number plate light is not working either so it appears everything connected to the main exterior light switch doesn't work so I will check connections there.

[dontuna]

Is this the resistor?? Thanks

[v8s4me]

That could be the ballast resistor for the coil - if your car has a ballasted coil. Although on my Tasmin the coil was ballasted with a big loop of wire which over the years had melted itself into one bit blob.

My dim/dimmer resistors (2 of them) on the V8S were bigger than that.

[phillpot]

If your car has he 2.9 engine it won't have a ballast resistor on the coil so that is more than likely it, although as Joe says, usually there are two wired in series?
Pull wires off and join together, although even if faulty it shouldn't stop dash lights working on "bright" setting.

https://www.ebay.co.uk/itm/111584292050?hash=item1...

Edited by phillpot on Wednesday 12th July 07:38

[dontuna]

Thanks for all the input. Still no joy. I have the 2.9 engine. Only one resistor compared to your two. Who knows why. Connected together and no joy. There is simply no power going to the interior dashboard light circuit when ignition on and main lights turned on. I've checked fuses but they are a little all over the place with rewires here and there so who knows!! Does anyone have a wiring diagram for this and also could confirm which fuse should apply to this circuit. I'm based near Milton Keynes if anyone is close and could help!!!! Beers on me

[phillpot]

Been a few fuse board layouts, best just check them all.

Wiring diagram is in Steve Heath book or can be found online.

Have you got live to the off/dim/not quite so dim switch (red/white wire)?

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[dontuna]

Thanks. It would appear I do not have power to the red/white wire in the back of the on/dimmer switch for the interior lights. Does lack of power here stop the lights from turning on? What next??? Thanks again. It's frustrating as the MOT is in a week so need to resolve ASAP

[v8s4me]

If there's no power going into the switch then obviously there will be no power coming out the other side into the lights.

You'll need to trace the power supply wire back from the switch to find out where the break is.

You could fit a new wire to get power to the switch to make sure that once you have found the problem in the supply the light will then work.

Alternatively just run a new power supply from some other part of the lighting circuit and leave the dud wire where it is.

[dontuna]

Thanks for all the advise. I have traced everything back using the wiring diagram which was really helpful and found a rogue fuse which had failed!!! Don't you just live the quality of wiring in these cars. Mocked up a fuse and all came back on so a dud fuse in the end!! Have a great weekend all

[dontuna]

Does anyone know if this is the correct bulb for the dashboard back lights?

I also attach a photo of the original


Thanks

[dontuna]

It is the right bulb. All sorted and working. Thanks again

[v8s4me]

If you paint the bulbs with green ink you'll get a nice green glow behind the instruments.

[lancepar]

Alternative to paint.

[phillpot]

lancepar said:

Alternative to paint.

Forget where I got them from but I got some of those

[v8s4me]

If you use the little green condoms you'll need a brighter bulb as they let less light through compared to green ink