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Morning all!... im trying to fault find my non working wipers my C3. Looks like they have not worked for many years (or decades!) so the time has come to fault find as I suspect there are several issues going on. The vac side looks good apart from the vac solenoid on the rear of the tacho. It has 2 terminals (yellow and blue wires) and an earth connection on the body. At present there is 12volts on both yellow and blue whenever the ignition is turned on (and regarless of wiper switch position) and no voltage when ignition off. Also I can blow through the solenoid with voltage AND with NO voltage so I suspect its faulty.
How can I test solenoid correctly? should the vac "switch" be open or closed with no voltage? should both terminals have voltage?
Where can I find a wiring diagram for the wiper system?
Many thanks and greetings from lockdown UK
Can't remember whether the solenoid is open or closed with power but it is easy to open and repair/clean (provided the coil is OK). The valve/seal get dirty over time and is not blocking the vacuum anymore.
Greetings from Boston USA first thing to check is the wiper override switch under the steering column is in the ON position
Im glad you mentioned this as it was not allowing voltage across it in either position!. Its fixed and working correctly now with 12 volts ignition on or off. I also have 12v at either side of the wiper door limit switch with door open.
Can't remember whether the solenoid is open or closed with power but it is easy to open and repair/clean (provided the coil is OK). The valve/seal get dirty over time and is not blocking the vacuum anymore.
Thanks....I'll check it out. Great photo..i'm all for taking stuff apart to see if its fixable
UPDATE: So the vac solenoid is working. If I hook up 12v direct to the yellow terminal(15) and earth to the blue(16) it clicks and closes the vacuum port. At present there is power on both yellow AND blue with ignition on. So something is not changing the 12v to earth on the blue terminal(16). Possibly the relay?..The investigation continues
1972 Wiper fault finding
