Rear light contacts

Definitely not anything with copper in its name!

Vaseline if you must; proper contact cleaner is better.

Chris

Contact cleaner will leave it totally grease free, whereas vaseline will protect it a bit. However, corrosion on the contacts suggests that you have a problem with water ingress - either round the lamp seals or a general damp problem in the car. I've not seen corroded connectors on my MK2 Golfs, which are older than the OP's BMW. 3M Body Caulking may be a good solution if the seals on the lamp have perished.

The only damp problem I'm aware of is on two occasions a stray beer can has emptied itself in the boot. They are so flimsy these days. I don't think the seals are at fault. When I unbolt the light clusters I can't get them out the seals are so stuck.

Strange it is the 21 Watt bulbs that get intermittant use. Brakes and indicators. Maybe I'll just go for a bit of Vaseline. If the present lights have lasted

Every contact cleaner I have used in the last 45 years has had the property of leaving an electrically safe lubricant in place. These have included brands such as Servisol, Electrolube, and RS's own.

Perhaps you were thinking of a degreasing spray?

Chris

In message , Chris Whelan writes

Really? Quite a few I've used didn't. Colclene TF being one.

"de-Oxit Gold"

Do you have a reference to what its makers describe it as?

Only one I can find is Colclene PCS, which is described as an electronic cleaner/degreaser.

Chris

In message , Chris Whelan writes

Might not be available any more, I think it was a nasty ozone depleting chemical (that's how long ago it was) but it was excellent stuff that dealt with pots and switches most if not all the others couldn't.

Vaseline, I've always used it on truck lights and contacts, which are out in the open and subject to getting soaked by salty spray, never had any problems.

The only theoretical problem is that Vaseline being petroleum based could cause some seals to swell, or perish, but I have never known this occur.

Check that the correctly rated bulbs were/are fitted. Have 21W bulbs been fitted instead of the correct 5W or 10W? Dave

If its brake lights or indicators as stated in the OP, then they should be

Wasn't it possible to fit a 21W/10W dual filament bulb the wrong way round (in the old Cavalier) by forcing it in? So that the tail light was lit with 21W and the brake with only 10W? The bulb holder would then melt? Dave

Kellerman