C3 W/S wiper solenoid

[Ed Driscoll]

Hi guys,
I remember someone saying somewhere that if the w/s solenoid energizes when the system is off, but hot, that this indicates a bad solenoid (mine ticks everytime I connect battery power to the system, and ticks again on disconnect, key in off posistion). As this is happening and the solenoid has just arrived from an unnammed supplier, I'm in need of advice. Can anything else be causing this?
Also, what actually constitutes good vacuum retention. If my headlamp switch looses vac very, very slowly, ( over 2 days) is it still bad? Do these switches actually hold all of the vacuum in the system indefinitely?
Thanx
Ed

[Harmon C.]

Vacuum system

Ed If the complete vacuum system can open the headlights after fifteen minutes with the engine off I would say it is good and if they close also it is a very good system.

[Jon S.]

Re: C3 W/S wiper solenoid

I assume you mean the solenoid mounted on the back of the tach. This should not be energized with the wiper switch (or car) off, and should allow vacuum flow between the two vacuum ports on the solenoid. With the wiper switch off (and the wipers parked) this in turn allows the vacuum to flow through the override switch to the interlock switch under the wiper grille and then to the relay and keeps the door closed. Open any of those switches (or energize the solenoid by turning on the wiper switch) and the wiper door will open.

Have you tested it off the car? If the solenoid is in the car, and it is energized whenever you connect the battery, I would suspect the solenoid wiring or the wiper switch (which I believe feeds the power to the solenoid) rather than the solenoid itself.

As for retaining the vacuum, they will all leak down over time. The PV manual tests for being able to close the headlights 30 seconds after shutting the car off and says that a very tight system will do so after 30 minutes. If yours will do this after 2 days, I would count your blessings.

[Jim T.]

Re: C3 W/S wiper solenoid

After reading your msg I wanted to check your profile to see what year of C3 you have. Glad I did, because from my experience it does make a difference. I drove my original owner 68 twice yesterday. It is really a good ole 35 year old car. Now if I were to shut off the ignition and accidently turn on the wiper switch, in cleaning the dash, and then just return the switch to off, you would think everything would be just fine. It is not, what would happen is that in a given amount of time my battery would be run down because the wiper switch was activated. Does not matter that it was turned off. Because I know my car, I moved the wiper switch from off to on and back off with the car not running. From prior experience I know this will run down the battery. I have to start the car and turn on the wipers and then turn them off with the car running. Now the circuit is really off and will not run down the battery when the car is turned off. I have never experienced this problem with my 70 and believe this is just a wierd problem of my 68. Knowing this problem, I have not accidently turned on the wiper switch in about 20 years.

[Ed Driscoll]

Re: C3 W/S wiper solenoid

Jim,
Thats a real "ghost in the machine" problem. Does anyone know how the curcuit is managing to do this? How is this possible? (electro magnet somehow staying magnetic after current is interupted?) I did turn the overide switch on and off yetserday, although I didn't notice wheather it was making any sound. Also, can the switch be 180 degrees out? there were no tabs on the contacts, so I'm going to flip the connector and see if that helps. What color is the inside (tach closest) wire?
Thanx
Ed

[Ed Driscoll]

Re: C3 W/S wiper solenoid

Jon,
Do you know a protocol for testing the wiper switch.
Thanx
Ed

[Jon S.]

Re: C3 W/S wiper solenoid

Mine was hooked up with the blue wire toward the firewall. To answer your previous question, no. Unfortunately I don't know a sure way to check the wiper switch.

You mentioned the override switch though. Is it possible that this (the round knob, not the door override) was switched to stop the wipers when you did your test? I believe that would keep the solenoid energized - but I'm not positive.

[Jim T.]

Re: C3 W/S wiper solenoid

Ed I have finally been able to get under the dash of the 68 and look at the windshield wiper vacuum solenoid. The bottom wire is black and the top wire is brown as viewing my vacuum solenoid switch looking up into the back of the dash area. The vacuum solenoid is only connected to vacuum hoses and the two wire electrical connector for stationary support. My wires are in a plastic connector attached to the vacuum solenoid. Are these the wires you had the question about? The solenoids electrical terminals point towards the center console.
Tomorrow I think I will turn on my wiper switch with my digital voltmeter connected to the battery and see what happens.
Then I am going to start my 68 after turning off the wiper switch and see if it cycles the wipers with the wiper switch off.
I have always started the car and cycled the wipers if I accidently turned the wipers on with the car not running, but cannot remember if they would cycle without turning the wiper switch on when the car is started.

[Jon S.]

Re: C3 W/S wiper solenoid

Sorry if my wire colore response caused you confusion, Ed. I didn't notice you had a '68. Mine is a '69 and the wires are apparently a different color (yellow/blue) than what Jim describes. My solenoid is also attached to the back of the tach with two screws, so there may be more differences between the two years.

Jon

[Ed Driscoll]

Re: C3 W/S wiper solenoid

Jim,
I'm still unsure where the energizing is coming from. When I pull the wiper moter out of the curcuit, the solenoid is not energized, but when the hot wire is reconnected to the wiper motor, it energizes. It all seems a bit mysterious to me. I guess thats all a part of it. Thanx very much for all the help.
Ed

[Jim T.]

Re: C3 W/S wiper solenoid

Ed I did the test I mentioned this afternoon. Having the digital voltmeter connected to the battery and turning on the dashboad wiper switch did not draw any current. I still started the 68 and cycled the wipers anyway. I do know that many years ago I was cleaning the dash and accidently turned on the wipers and put the switch back to off. Couple days later went to drive the car and the battey was drained. Perhaps I have been wrong to blame the drained battery on the switch. I don't know, but I will continue to start the car and cycle the wipers if I accidently turn on the wipers when not driving the car.

[Ed Driscoll]

Re: C3 W/S wiper solenoid

Jim,
today I pulled the dash harness off and found a short. unfortunately, it wasn't in the wiper circuit. This cycling of the wipers to disengage the solenoid is bugging me. Something interesting in the wiring of the wiper motor though. When I disconnected brn/w from the wiper motor, the solenoid de energizes. I'm now going to sit with the schematic and isolate the circuit to see if I can find out where current is coming from. so far, I'm a bit stumped. I'll give you the update.
thanx for the help
Ed