Topic: Vacuum Wiper Door Ghost
in Forum: C3 Body
Already a Member?
Click Here to Login
Not yet a Member?
Click Here to Register for Free!
Hi Folks, working out the bugs now that I finally have the car moving.
The wiper door opens by itself after the engine is shut off. Only halfway or so, takes about an hour or so for it to creep up.
Everything has been replaced, vacuum lines, 3 vacuum switches, headlight motors, seals in wiper vacuum motor, check valve etc. This did not happen with the system before I tore the car down.
Troubleshooting the problem, I put the old, crusty, rusty wiper vacuum motor switchback in and it works ok.
Everything works normally, headlights and the wiper door, just creeps up after an hour or so. I am lead to believe that the new switch is leaky? Might take one of the headlight switches and swap to see if it is in fact bad.

The wiper door opens by itself after the engine is shut off. Only halfway or so, takes about an hour or so for it to creep up.
Everything has been replaced, vacuum lines, 3 vacuum switches, headlight motors, seals in wiper vacuum motor, check valve etc. This did not happen with the system before I tore the car down.
Troubleshooting the problem, I put the old, crusty, rusty wiper vacuum motor switchback in and it works ok.
Everything works normally, headlights and the wiper door, just creeps up after an hour or so. I am lead to believe that the new switch is leaky? Might take one of the headlight switches and swap to see if it is in fact bad.

SPONSOR AD:: (Our Sponsors help support C3VR)
It sounds like you do have a leaky switch. I would do just as you suggest, and put the other one back in place for a trial.
I am trying not to over think this problem, but something bothers me about the control circuit for the relay. Troubleshooting this, I put a vacuum gauge on the small line to the relay, and it measures 6 lbs. I was surprised at this, thinking that the vacuum would be the same everywhere ( 18lbs at the carb ) in the system if everything is good. Vacuum at this line equals door closed.
Has anyone ever actually measured this or could measure for me?? I will try to swap out the new relays today and see what happens anyway. Thanks
Has anyone ever actually measured this or could measure for me?? I will try to swap out the new relays today and see what happens anyway. Thanks

in Forum: C3 Body
SPONSOR AD: (Our Sponsors help support C3VR)