Dashboard instrument lights not working

[suffolkfox]

After my little shrub murdering spree www.pistonheads.com/gassing/topic.asp?t=359678&f=12&h=0 and subject to the suspension and tracking checks being carried out today, the only problem left other than replacing the spoiler is the dash instrument lights don't work. I have checked all fuses are OK and everything else is operational including all lights except these (light in glove box works also). I am assuming it's a connection so does anyone know:-

- where the earth connection for the instrument lights connects
- which connector in the wiring in the dash supplies power to these
- any other bright ideas (sorry for pun)

On a positive note, my reversing light switch that had got stuck has now been freed by the impacts so I have put the bulbs back in and I can now see backwards at night, just no idea what speed I'm doing forward .
Cheers
Jerry

[digga951]

You have checked the little rotary switch on the RH side of the steering column haven't you, the one that adjusts the brightness. May even be worth taking the top half of the shroud off and shorting the two wires together as the switches do sometimes break.

Check this first

Dan.

[adam quantrill]

.. or it could be a rheostat, which gives a continuous adjustment, but if it has burnt out it might be open circuit.

If you find one of the dash lights (the easiest one to access might be the fibre optic bulb) then check for +ve volts with the sidelights on. Then you can work out if its the earth or the switch side that's broken.

[phart]

I think the earthing for the instrument lights is through the bonnet release cable, and then an earth strap from the latch to the engine block?

[brap_brap]

digga951 said:

You have checked the little rotary switch on the RH side of the steering column haven't you, the one that adjusts the brightness. May even be worth taking the top half of the shroud off and shorting the two wires together as the switches do sometimes break.

Check this first

Dan.

I don't know the construction of the dimmer switch but if it's anything like the one in my mazda
shorting the leads for testing can blow every light in the instrument panel due to a lack of
protective resitance....or so says my mechanic. If I were going to take your advice I think
it would be safer done through a 1/4W resistor of a rating at least 3/4 the total impedance of the dimmer.

[suffolkfox]

Excellent & thanks all, will have a rummage this evening. Wrt the fibre optic bulb, excuse ignorance but what/where is it. Seen it mentioned here a few times but there is nothing I have seen in and around the instruments that I could equate to this.

[digga951]

Pull off the pice of trim where the passengers right knee would be, the bit that runs from the radio/switch panel up into the footwell. Its under here. Normally a silver and black cylinder shaped thing with lots of wires coming out of it!

Edited to add:- Its sometimes easier to remove the radio/switch panel cover (undo screw on either side, then just pull off), then swing the footwell trim downwards.

Dan.

Edited by digga951 on Monday 26th February 14:09

[suffolkfox]

Dan, your first comment was correct, I touched the dash light brightness knob and it all came on (bit like the 'engine is dead - have you checked to see if you have any petrol sir!'). In my defence however, the effective adjustment in the virtually 360 degree rotation appears to be the last 2 degrees which acts like a switch taking me from off to on. May take it out and spray in electrical contact cleaner to see if I can get a slightly wider adjustment range.
Thanks again til next time

edited to add Meant to say all passed AOK in suspension check, bit too much toe-in and couple of balance weights missing off wheels is all but all happy now

Edited by suffolkfox on Monday 26th February 17:48

[350zwelgje]

suffolkfox said:

Dan, your first comment was correct, I touched the dash light brightness knob and it all came on (bit like the 'engine is dead - have you checked to see if you have any petrol sir!'). In my defence however, the effective adjustment in the virtually 360 degree rotation appears to be the last 2 degrees which acts like a switch taking me from off to on. May take it out and spray in electrical contact cleaner to see if I can get a slightly wider adjustment range.
Thanks again til next time

edited to add Meant to say all passed AOK in suspension check, bit too much toe-in and couple of balance weights missing off wheels is all but all happy now

Edited by suffolkfox on Monday 26th February 17:48

Same on mine: last part of the variable resistior switches dash lights on/off...
As long as it works, it is fine by me.

Rob

[digga951]

Glad you got it sorted. My switch used to only have an off-on range, so I removed it. I just joined the feeding wires together so that the dash lights worked, and I installed my engine fan toggle switch in the hole!

[leorest]

Mine has a variation from ineffective all the way up to "too dimm to see" with a couple off positions along the way. Just try to find the least dim setting and leave it there!
A little tip from SA

[GV]

Is there a way to bypass the original circuitry on the intrument lights for a more reliable set up? Mine make their own decisions as to when they decide to light themselves up....little bastads...lol.