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2 brake light switches?

Posted: 15 Jul 2014, 21:39
by mr.mono7
Evening,

Does anyone know why there are 2 brake light switches?

I've got the mot tomorrow and the brake lights have packed in. I got them working briefly and noticed that when I disconnected the switch nearest the steering wheel, the lights still worked?

Was thinking of swapping the 2 switches about to see if that works if possible? Either that or just hope the switches decide to work for the test!

Any thoughts?

Re: 2 brake light switches?

Posted: 16 Jul 2014, 05:27
by itchyfeet
Haynes shows them wired in parallel
if it works with one disconnected thats strange but do it for the mot and replace later

Re: 2 brake light switches?

Posted: 16 Jul 2014, 06:45
by nevill3
When I replaced my brake master cylinder the new one I purchased had two openings for a brake switch but my old one only had one switch. I was unable to buy a blank for the extra switch hole so I just inserted an extra switch but it isn't wired to anything. I think the early vans only had one switch but you don't say what van you have.

Re: 2 brake light switches?

Posted: 16 Jul 2014, 16:44
by TONYT25T25
Not sure but think there are two in case one half of the master cylinder fails, therefore still allowing part of the brakes to work, as they are pressure actuated it maybe worth bleeding the system and testing for any leaks.

Re: 2 brake light switches?

Posted: 18 Jul 2014, 22:12
by mr.mono7
I got up early and messed with the wiring some more, cleaned the contacts into the back of the fuse box and it seemed to do the trick. Will keep an eye on them and see how we go..

Oh, and it passed. Straight through first time of asking. :D

Re: 2 brake light switches?

Posted: 18 Jul 2014, 22:13
by mr.mono7
Oh, and thanks for the replies. All good stuff.

Re: 2 brake light switches?

Posted: 18 Jul 2014, 22:18
by R0B
The reason for two switches on the master cylinder is because these vans have a dual braking system,and therefore need two switches.
One for each circuit.