[urq] Brake System Failure Warning

[Maurits Jonkergouw]

Hi guys, this time I really don't how to fix this "challenge" lol. 


Challenge: 
'Fake' Brake System Failure warnings (voice and idiot light).

Checked:
A. black/purple connector behind the radio > it was already disconnected.
B. wires+connectors brake switch > tested OK with dummy switches.
C. warning switches (bottom) and (side) > tested OK with dummy wires and multimeter.


My understanding of the warning system and those switches is this: the side switch will 'close' if the brake accumulator (bomb) would completely lose pressure and the bottom switch will 'close' if the hydraulic pump fails with running engine. Otherwise, both switches are in the 'open' position with running engine only?

To verify the switches, I hooked up dummy wires and a DMM to each switch and test drive the car > both switches stay 'open'.

To verify the wires/connectors, I hooked up 2 dummy switches and test drive the car > manual switch 'open' : no voice warning > manual switch 'close' : voice warning and idiot light.


Conclusion:
I 'faked' the behavior of the switches/connectors and they are working fine during testing, but if I connect the 'real' connectors, the voice warning is triggered after approx. 5 or more minutes of driving...

Question:
How is this physical possible? I presume the switches are simple 'on/off' switches and not 'sensors' like like the oil pressure warning sensor?
I also noticed the bottom switch does sweat a little bit and perhaps the connector is filled up with hydraulic fluid after 5 minutes, 'shorting' the connector as if it was closed?

I appreciate your help as always...

Regards,
Maurits

1986 quattro GV (rebuilt)