On my 70 coupe my wipers now act up. The wiper door always opens and closes correctly upon turning the dash switch on or off. The problem lies with the wipers sweeping the windshield. Sometimes they come on, sometimes they don't.
When they don't come on, the wiper door is fully up and I hear a click sound from either the dash area, or the wiper motor cover area. If I turn the switch on or off a few times, sometimes the wipers will work.
Once when they were working fine sweeping the windshield, when I turned the switch off, the wipers stopped on the windshield without going to park position and the wiper door closed on top of them.
Can anyone explain the seeminly complex system of relays and switches. Any ideas what to do, how to troubleshoot? Thanks for your time to reply.

 

Sounds like a ground or dirty connections problem. Unplug the motor and clean the terminals. Disconnect the ground (screw on washer cover - drivers side bottom) and clean and reinstall. If it still doesn't work make sure the switch is grounded properly or run an extra one. If still doesn't work the run an extra ground to the motor. If it still doesn't work... well... lets hope it works then.

 

OK, I presume you have to understand the function of the vacuum relay, I call it the master controll valve....
the control section has ONE small hose, the main power section has 3 hoses...one is the main suck hose, the other two go to either side of the vacuum canister motor....when the control hose is disconnected the spring puts the main vac source in the door UP position...default setting....
when the vacuum is supplied to the relay control, it changes state and the main suck hose goes to the other side of the motor, and door goes down....
now, there is a vacuum switch on the pass wiper blade down at the pivot point...IF the system is off....the suck hose is disconnected from the canister, and door goes down.....if the system is running, the blades never go down far enough to lower door by releasing vacuum to the relay....
now there is a safety switch on the door that only allows the wipers to run IF the door is in the up position....it's a main powere 12 volt interrupt....
the vacuum relay in side under/behind the tach is in the controll circuit, activates to turn on the system.....operated by WSW switch....
you have a SEPARATE 12 volt feed which is the yellow wire to the WSW switch and motor unit in TWO places...the pump and the center terminal of our 3 term connector.....
the rest is really easy....seriously...

GENE

 

thanks for the info. I'll try cleaning all connections first, and the grounds. If no luck, I'll try and follow Gene's schematics. I'll let you know how it goes.

 

mine was doing the same thing-the motor was on it's way out. replaced it and the switch for around $400 new-but you can try a rebuilt one for much less and put it in yourself.

i had mine put in-it's the girl-thing:) (gotta protect the nails too!) haha

-Leslie