Hello, Got the MOT booked for Friday and the pickup seems to be putting up a fight. The brake lights stopped working so I got two new switches and bunged them in. The brake warning light lit up.... never seen this on before but it seems to work now. I'm assuming because both of the switches were duff. Brake lights were working but permanently on Then i got underneath the bus to see what was going on and to see if I'd plugged something back up wrong. that's quite difficult as they have 3 pin plugs. I noticed that one of the rubber boots was dripping. pulled the plug and realised that the switch had blown through. went down to Karmann conections and got another switch. stuck it in and bled everything. pressed the brakes and now have brake lights. Now my problem is that the brake warning switch is on when my foot is off the brake but goes out when I press the brake. There's no leaks anywhere and the entire system has been bled. The handbrake warning lamp never worked but this has now mysteriously fixed it'self. any ideas??? My thoughts are that one of the boots is still full of fluid which is completing a circut.... sound possible. my fist of straws seems to be dwindling. I could disconnect the offending +v wire from the back of the light but that's not fixing the fault. I'm pretty sure it's electrical as the whole system has been flushed with new fluid now and each corner is pumping nice clean fluid into the bottle. there's not spnge in the pedal either. cheers Dave
I was under the impression that the brake warning light comes on when there is a pressure loss in the system...I don't think brake fluid would conduct but I've never tried it. does the BL Warning lamp stay on when the engine is running and your foot's off the pedal? can you pull up a wiring diagram for your model? could be that the +ve and -ve connections are back to front
that's what I thought vanorack. The light is on until I put my foot on the brake pedal then it goes out. The 3 pin connector plug was full of fluid from the faulty replacement switch and sits in a rubber boot. I suppose it's possible that it's wet inside the boot. Ive tried it with the engine running and without. bled it all twice and have pumped over a litre of new fluid in total. I can understand the light being on when I go to brake, giving a warning that something is loosing presure but it goes out when I brake. I dont know how someone could have swapped the two wires unless they've taken the boots off. bit confused... I cant really road test it until Friday morning as it's on a sorn at the moment. but
I was just wondering whether the warning light came on with the ignition, and then goes off when it boots up....and comes on again if there's a problem, but obviously not. just done a search to see if Brake fluid conducts electricity and apparently it doesn't....but, if the negative terminal on the switch relies on the body of the M Cyl to act as it's earth, and the screw threads in the body are corroded, then maybe it's not earthing properly....just a thought
yeah i read that about it going off, it could be that the wiring has been messed with a bit. it might be that there's air in one of the switches. I'll have to get up early on friday and take it for a longish spin before the MOT and check things over. I'm hoping that what ever it is may be something air related. just odd that it goes off when i put my foot on the brake, I'd have thought it would be the other way around. cheers for your help anyhoo's
