Just faulty wiper switch?
Thread Starter
Drifting
Joined: Jul 2012
Posts: 1,255
Likes: 297
From: Slovenia, EU
2017 C3 of Year Finalist
Just faulty wiper switch?
If I use wiper switch on my 71 the wiper doors won't open. If I use override under the steering wheel to open them they work like a charm and wipers also work.
Why then don't the doors open with switch on the console? Is it just a faulty wiper switch?
Why then don't the doors open with switch on the console? Is it just a faulty wiper switch?
Team Owner
Joined: Sep 2006
Posts: 31,283
Likes: 4,374
From: Westminster Maryland
Hi P,
I believe you'll find that the over-ride vacuum switch bypasses the wiper door solenoid that's mounted on the rear side of the tachometer case.
If you look at a vacuum diagram you'll see how the bypass is done, and why the wiper door opens.
Regards,
Alan
I believe you'll find that the over-ride vacuum switch bypasses the wiper door solenoid that's mounted on the rear side of the tachometer case.
If you look at a vacuum diagram you'll see how the bypass is done, and why the wiper door opens.
Regards,
Alan
Drifting
Joined: Jul 2006
Posts: 1,259
Likes: 154
From: Deplorableville Nebraska
Atmospheric pressure must be allowed into the wiper door control circuit for the door to open. It is achieved one of two ways. 1 - The solenoid is energized by the switch thus allowing atmosphere into the circuit through the port with the filter in Alan's picture. 2 - Atmosphere is allowed into the circuit by pulling on the override switch. It is important to note that either operation also blocks vacuum from entering the source hose in either component.
The solenoid can easily be checked. It is located on the back side of the tach. You should hear an audible click from it when it is energized. This is best done with the engine off, and ignition on. If you don't hear a click, connect an ohmmeter to the two contacts and try the switch. If no go, then it's probably the wiper switch on the dash.
Here's a picture of the solenoid location....
The solenoid can easily be checked. It is located on the back side of the tach. You should hear an audible click from it when it is energized. This is best done with the engine off, and ignition on. If you don't hear a click, connect an ohmmeter to the two contacts and try the switch. If no go, then it's probably the wiper switch on the dash.
Here's a picture of the solenoid location....
