Brake lights not working, glowplug light and engine management light flashing, all bulbs are OK - taken out and tested both in and out of the car, I bought a new VW black bodied brake light switch and fitted but still no brake lights. I have just tested the switch off the car but cannot get any response from it apart from pins 2+4 create a permanent circuit, and it stays a permanent circuit if the plunger is pushed in. Anybody any ideas apart from it being a 'duff' switch.

 

DB

Fuse checked?

Yes F2 fuse checked.

 

DB

With respect to check the functioning of the new switch, as far as I know and have experienced, you will make no sense out of these switches electrically unless you hold the right part and rotate it the switch as it would end up when fitted to the car.

 

One other thing, how did you fit it, the correct way to fit these latest switches is to leave the brake pedal in the fully "up" position and fit the switch in the usual way. This is the opposite of the method used to fit the previous switches, if you have fitted it incorrectly, you will have "locked up" the switch in the off position, it will still be okay to use though, just remove and refit as I've suggested.

Yes the switch was fitted correctly, I now also understand that the cruise control had ceased working too.

 

DB

Still pointing towards a faulty / incorrectly fitted brake pedal switch then.

Have you checked the how to / guides to changing them to make sure it's correct?

Having just looked at the switch again, I can now see it needs to be fully turned clockwise, I failed to turn it the last bit because it felt so tight, so I will try some spinach in the morning and have another go.

DB

Every time I see an electrical fault of this type ,i see a lot of conjecture etc on cause. WHY not approach it logically. You won't need a meter, just a lamp . In the case of brake lights ,i'd suggest a brake lamp, on a bit of wire. Start at the lamp end . Does meter say 12v, or lamp light , with pedal down ? . Yes- problems with tail unit. No - problem further back( suggest a look in haynes ,OR BUY ONE) for further places to look .

VWD - have done all the checks you suggest and yes, I have a well thumbed Haynes manual but it fails to highlight much info on the brake light switch.

DB

hutchysrs50

 

Thanks, you were quite right, I fitted it once again and it turned CW more easily, all checked out OK.

 

DB

No problem, your welcome.