Faulty brake switch

[Dave B]

Guys,

Preparing my CSi for another summer of fun. Seriously considering the UK meet, but it will be hundreds of miles for me. Will depend on the date and location being finalised - I am now a shift worker again!

I have a faulty brake switch. Sometimes the brake lights come on - sometimes they dont!!

Wiring is ok, bulbs are ok, problem is the switch at the pedal. A mechanic friend has told me to get a new switch. Are these pretty generic things? Will a BMW dealer/stealer rip me off cos I say e9??

 

[velocewest]

Say e3... 8) Same switch. They're cheap.

 

[30csl]

Hi Dave, mine is a bit dodge too but i just put a cap over the end of the switch as it seemed not to be coming out enough and that did the trick. Perhaps yours is the same problem.

 

[Honolulu]

Dave, you gotta know

that the tail light assemblies frequently have a bad ground bar. It looks okay but it's steel and the rivets holding it to the bulb sockets are brass. Ergo, dissimilar metals, galvanic action, preferential corrosion, whatever you call it, the socket loses ground and although your can prove with a test light that the socket is getting power and that the bulb is good, it no workie.

Jigger around with the ground bar near where it's riveted to the socket that won't light, and see if the light comes on. If so, there are several possible actions. One, drill our and replace the brass rivets with something else. Two, run a separate ground from each socket, or a wire providing a secure ground to each socket in series.

It's unlikely to be the switch, but you easily test a switch, and can reposition them to restore function. But anyone with a coupe will recognize that.