E30 Zone

They used to be temperamental, but now the little light for the front fogs on the dashboard doesn't come on, or the fog lights themselves.

The bulbs are okay, so I assume it's the relay or the interior switch itself?

I have taken both out and checked the connections and they're clean.........

Any ideas please?

Anyone?

Do you have the combined switch, or the individual switches for front and rear?

The standard way of checking the lights is to remove the switch and bridge together the wires to make either the front or rear fogs come on - IIRC it's the grey wire that needs 12V, but a search will confirm.

A good blast of contact cleaner inside the switch will clean up a temperamental one.

The first point to make is that the foglight wiring on an E30 has a few variations, depending on market and local regulations, so if yours is a French spec. E30, there may be variations.
The tell tale light on the dash is connected to the 'out' side of fuse 29, so it's probably safe to assume that there's a fault before there.
Pull out relay K8 (one of the two square black ones) in the fusebox, identify pins 30 and 87 of its socket (marked on the relay), and then link these two together with a short piece of wire.
This should result in both foglights and the tell tale being lit.
If it passes this test, replace the relay, pull out the foglight switch, unplug it, switch the ignition on, and use a piece of wire to connect the grey wire at pin 7 to earth.
If this makes the lights come on, use the piece of wire to connect the grey wire and the grey/blue on pin 5 together.
If this makes the lights come on, it's time to strip down the switch and clean it up.

I appreciate the replies, guys

She's an E30 I bought over from the UK so I'll do the checks you suggest and hope it works.

Thanks again

Brianmoooore wrote: ↑

Sat Jun 22, 2013 10:15 am

The tell tale light on the dash is connected to the 'out' side of fuse 29, so it's probably safe to assume that there's a fault before there.
Pull out relay K8 (one of the two square black ones) in the fusebox, identify pins 30 and 87 of its socket (marked on the relay), and then link these two together with a short piece of wire.
This should result in both foglights and the tell tale being lit.
If it passes this test, replace the relay, pull out the foglight switch, unplug it, switch the ignition on, and use a piece of wire to connect the grey wire at pin 7 to earth.
If this makes the lights come on, use the piece of wire to connect the grey wire and the grey/blue on pin 5 together.
If this makes the lights come on, it's time to strip down the switch and clean it up.

My front and rear foglights were non functioning - and this advice is spot on.
Checked the fuses = all good.
No clicking at the relay = jumped the relay and the lights came on
Must be the switch!
And after disassembly... yep.





There's ya problem!

In case others have the same problem, avoid the temptation to sand down the contacts.
You'll just introduce grit and contamination - Best to chemically clean.





Here's a quick home recipe for cleaning copper switch contacts.
You'll need three small containers, a few small brushes and cotton tips or cotton buds.

A. Acid solution
Add 1 tablespoon of salt into 1 container.
Fill with vinegar - doesn't matter how much vinegar, you'll need to dissolve as much salt in the vinegar as it can handle.

B. Neutralising solution
Add 1 tablespoon of Sodium Bicarbonate, (baking soda) to the other container.
Fill with water and stir.
Add more baking soda to make it cloudy.
Again, the exact amount isn't important - the bi-carb solution will neutralise the acidic cleaning solution.

C. Wash down
Fill the last container with isopropyl alcohol (IPA) preferably 99% IPA.

Disassemble the switch.
If your switch contacts are greasy, dip a cotton bud into solution C. to dissolve the grease.

Take the small brush or cotton tips and dip into solution A.
Wipe on the contacts and agitate - may need a few dips into the solution.
If badly oxidised Will take a few minutes or so.
You'll need to keep applying solution A. to keep cleaning.

When you're happy shake off the drips and use the brush to apply solution B.
You only need to apply and agitate to stop the acidic process.

Best to rinse off the part in solution C. to get rid of any baking soda residue (otherwise you may have a dusty residue).
Shake off and let the part dry.

Rinse & repeat for the other parts.

Reassemble and you're all set!
Optional to add some conductive grease to prevent corrosion & peace of mind.
I'd avoid dielectric grease on these switch contacts as dielectric grease is an insulator and if it's silicone based can lead to arcing.



Ready for another 30+ years.

I had a similar issue with the rear fog light - turned out it was the switch. Start there. Easy to disassamble and clean the contacts and put back.

It was 7 years ago, I reckon he's cracked it by now