Cruise Control

[Mauser]

My cruise control has gone kaput, it was working fine then died due to the normal persihed pipe I soon repaired this fault and all was well, now it has gone again but even with new a new pipe it still won't engage. Have removed the pump and it works fine when i supply 12volts to the motor, when driving @ more than 30 and I pull the stick to out to turn the cruise on the relay on the near side behind the dash clicks then drops straight out again, don't know if it is supposed to do this or not, I would say the speed sensor is OK as it doesn't click @ lower speeds. Which brake pedal switch controls the vacuum line ?, my motor is an auto so might be different to the manual ones.

Bit baffled why it does nothing, normally as long as it's on and when I press the end of the stick in it works fine, could do with it working soon as going to London and would be handy, there is a solonoid / relay device within the pump body which either holds the vaccum or drops it when energised, cannot test which way without driving @ 30 and looking under the bonnet .

Any idea guys ?.

[tdi90]

brake light & clutch switch (if you aint got an auto) upbehind the pedals?