I'm in the dark

[e30nerd]

Leant the car to the girl-friend today, to find when I got in it thisevening that all the dash lights had gone

Checked the obvious like had she reduced the intesity down to 0, but no the headlight pull switch rotates fine with no differance.

Have checked fuses 10, 12 and 23 all fine, and other items run from them such as check control module and reversing lights all function ok.

Window switches (which are always on still work). What ever is the cause effects everything (ie dash panel lights, full trip computer illumination and m-tech illuminated gear knob).

The dials still function ok, the trip computer still lights the display when lights are off, but when you switch them on and the additional lighting on the trip computer kicks in and it blacks out completly (ie buttons and display).

I'm assuming it must be a fault with the rotating part of the headlamp pull switch.

Any suggestions guys?

[Brianmoooore]

Find the grey/red wire going to one of the more easily reached lamps, and apply 12V+ to it from the battery via a 5A or 7.5A fuse. I
If the lights all light and the fuse holds, then the fault is probably the headlamp switch.

[e30nerd]

Cheers Brian
I think it is probably the switch. I have a spare in the garage that I'll fit over the weekend. I just hate trying to refit that under dash panel above the pedals.

Reading up on it apparently the connectors on the back should have continuity when the headlight switch is in the on position between connector 58RE and 58K and continuity between 31 and 31H. Also you should be able to prove if it works or not, as if you adjust the rotating dash-light intensity knob the resistance will change.

I'm hoping one of them will be open circuit, therefore proving there is a fault.

I really hope that is it as I don't fancy ripping the dash out trying to get to the loom.

[Jesus325iTouring]

Mine has started to go off periodically,but a sharp tap on the dash restores them,not sure this will last to long though!

[e30nerd]

Someone else mentioed that - I assume they fail with age.

I have given mine a bloody good **ahem** bang!

But no luck - think I will have to try the more engineered subtle approach!

[Jesus325iTouring]

Someone else mentioed that - I assume they fail with age.

I have given mine a bloody good **ahem** bang!

But no luck - think I will have to try the more engineered subtle approach!

I think you right,keep your hammer in the tool box!

[wightE30]

OK, first thing is that I've helped E30NERD sort his problem (or should I say the cars problem), but learnt an interesting fact in the process.

Firstly fix has been to replace the headlight pull switch. Should you have to do this there are two fixings up behind the dash. 8mm nuts onto studs. The whole rectangular panel with headlight switch and fog light switch will come out. Once released you will have to rotate the whole unit through 90 degrees if you want to get the switch out without unplugging it.

When sourcing your replacement switch be aware that there are also a couple of different types of connector these switches were made with. I had a spare from an 85 model and the connector was a blade type, but E30NERD's was circular pins in rectangular moulding.

OK, key bit of info - it didn't fix anything when we put the swtich back in! It turns out that the double fog light switch makes part of the circuit. Appears that the GND for the dash lights passes through the fog switch. Reinstall the fog switch and it all comes good!

Don't get caught like we did by thinking you hadn't fixed the problem. Also means if you take out the foglight switch for some reason the dash lights won't work anymore!

[e30nerd]

All working good and proper again - thaks to all who helped.

The top rignt hand 8mm nut is a bit*h to get off and on again. It is up behind the dash at the limit of your fingers reach (and I have long fingers!)

- can't get a socket on it as there is no room, and is so tight against the headlight switch that to re-screw it you need to slide the nut at a 45 degree angle betwwen the head of the thread and the side of the light switch. All this has to be done working 'backwards' by touch alone, as metioned before at the limit of your fingers reach.

To sum up 30 seconds to replace the switch - approximatly 2 to 3 hours to do 1 poxy nut back up.

[Kedge]

It's those kind of situations that i nearly lose my rag and start looking for big heavy tools!

[e30nerd]

It's those kind of situations that i nearly lose my rag and start looking for big heavy tools!

I think for the first time ever, I've done some work on the car without removing all the skin from my knuckles

[ian332isport]

I think for the first time ever, I've done some work on the car without removing all the skin from my knuckles

You probably didn't do it right then