Just joined the forum and think it's great. Have a question for anyone who likes electrical problems. I am having trouble getting the wiper motor and door system to work properly on my 68. I have checked all the vacuum lines, everything works fine so my problem is electrical. I can get the wiper washer mechanism to work but not the wipers alone. I hear the relay "click" when I put it in either low or high setting but nothing moves. I have replaced every component and still nothing. The motor was bench tested and checks out. Does anyone have an idea about what's wrong? Is there some special procedure I need to follow after rewiring the car? Can anyone tell me which wires should be hot and not when I put the switch in the low or high position? Any help would be greatly appreciated. Going nuts :confused:

 

Did you also replace the wiper motor? I recently worked on a 68 that had a replacement wiper motor and it was the wrong motor. The motor and wiper switch must work together as a team, and this combo varied based upon year. If you were sent the wrong motor/switch combo, it will not work.

 

i had a elec prob in my 72. Traced it to a spade terminal on the safety switch wire. Wire passed current ..spade didnt..drove me nuts cos i wan testing all the wiring from the core. I found after 6 hours. Good luck.

 

Yes I did. After I restored the car, I bought new wiring and a new wiper motor(not rebuilt). I know I ordered one for a 68, but I am not sure how I can tell if it is right or not. Everything did wire up okay. Do you have any recommendations as to how I can tell if it is correct and what wires should be powered when the ignition is on and also when the switch is activated? (The motor was bench tested and it does work)

Also, if it is the wrong motor, would it prevent the wiper door from activating when I flip the switch? Currently, I have to bypass it with the vacuum switch under the dash to get it to go up. I did replace the solinoid switch mounted on the tachometer because I quickly discovered that the door would go up and down when I was just driving it around town!(But not when I used the wiper switch)

Thanks for your help.

 

Bellys72, another CF member had the same trouble with his last year, and he found out accidentaly it was because his wiper motor had a bad ground, you might want to check that.
Tom

 

Thanks for your reply. I did hook up another ground straight to the chassis just to make sure that that was not the problem. Unfortunately, it still did not work. Any other suggestions?

 

Just had problems getting my wiper to work, after hours of trouble shooting we found out that the connector on the NEW wiring harness from ElectricLimited had the 5 pins reversed. Swapped them back and everything is fine. :mad :mad :mad

 

Darrell, I had the same problem and spent many beers trying to fix the problem. It turned out the wiper switch itself wasn't grounded and the wiper imotor was not grounded properly. Once I grounded the wiper switch, I heard the "click" at the motor. There's two black wires coming into the wiper motor connector, inside the engine compartment, and they need a good ground. I ran a ground from the engine block and wedged it into the connector and everything works great now.

Good luck

Jeff

 

I have the exact same problem. My wipers only work when I press the the switch for wash. I changed the switch today but still have the problem. I have tried to ground the switch and and the motor without any results. This problem really sucks. I don't drive much in the rain but it would be nice not to worry about the weather everytime I take the Vette out for a spin. I am going to keep working at it but please, if there are any other suggestions, We would like to hear them.
Thanks
John

Oh buy the way...This is on a 71 and my vacuum door works fine..thanks again


[Modified by theandies, 8:11 PM 9/18/2001]

 

When the wiper switch is pressed it sends current to the tach solenoid which starts the vacuum system. Vacuum
is send to the vacuum module that pushes or pulls the wiper door open/close. There is a micro switch that gets
set when the door opens all the way. This micro switch turns on the power to the wiper motor.

GROUND.....Must have ground to both the wiper switch inside and the wiper motor.

There are three wires on the connector to the wiper switch inside. From the driver side they are:
dark blue, black and light blue.

 

Darrell- I bench tested the wiper motor for the 68 that I worked on as well. It worked fine on the bench, but when installed on the car it did not work at all... in fact, when the wiper switch was depressed, the wires started to smoke. It was the wrong motor for a 68. Some suppliers do not have their act together with wiper motors. They assume that they are all wired the same. They are not, and neither are the switches. Some switches are (+) side operational, and some are ground circuit (-) operational. I'm not saying that you have this problem, I'm only suggesting that you have to be absolutely certain that you have the correct parts for a 68, or you can burn up you harness, the new motor, and the switch. That post about the new harness being wired wrong is another indicator that you cannot rely on the vendors for correct parts 100% of the time. When I repair wiper wiring on C3's, I remove the console to get at the back of the switch to verify that the switch is doing what I expect it to do based on the electrical schematic for the particular year C3. The schematic is absolutely essential, even though I have found errors in those as well. Unless you have a great amount of luck, and find an obvious easy fix (very possible... loose wire, etc), then you will need someone who has a good understanding of basic electronics. Mechanics typically do not know the difference between a short circuit and a ground. An Amateur Radio operator (HAM) has a better chance of troubleshooting your wipers than most mechanics will. Start by obtaining the correct schematic for a 68, and go from there. Or, if you're not busy tonight, bring it over and I'll fix it for you.

 

I have a similar problem. When I bought my '75 last week the wipers worked. A few days ago I removed my counsel where the gauges and wiper switch are and painted my counsel, I also washed my engine. I then read this thread and decided to check my wipers. My wipers don't work no. I took everything apart and everything seems connected ok I even cleaned the contacts. When I turn my switch on I hear a click down by the wiper motor area, but that is it.
What the heck!

:(

 

:(

 

Racer-X,

Try running a separate ground wire to the body of the wiper switch. The wipers won't work if the switch isn't grounded.

Shannon

 

Check the wiper switch connector, fits either way but only works in one positon.

 

Wiper switch connector only fits one way because the connector is about 1/8" longer on one side so it can only fit in one way. :(

 

Where should I start? Should I buy a new motor and switch? I tried the grounding thing and still all I hear when I turn the switch on is a click down by the wiper motor area.

:(

 

:(

 

You are correct about one side of the wiper connector being longer than the other. But, at least on early C3s, a common complaint was after servicing the the gages etc, wipers quit working... cause was connector was put on reversed. If the wiper works at all but not when the switch is in certain positions, I would look to see if the connector is on correctly, esp. if I had just fooled with it.

With the wiper switch in either positon the two light blue wires should both have a ground, the light green wire is the speed select and should be ground for slow. Dark blue goes to the washer pump. Check it out!

 

BUBBA STRIKES AGAIN. Having purchaced a used switch thinking that the old one was bad and it didn't fix my problem, I sat down with a friend and broke out the schmatics. We played with the old switch and determined that it was good. After going though the circuit on the car and schmatic it we decided to reverse the connector at the switch. The connector was originally plugged in correctly. With the switch plugged in "backwards" everyting works great!! :D :D :D . Bubba either rewired the switch connector or miswired the system somewhere else in the circuit. I don't recommend switching your connector just because if it is correctly wired you might burn up something or blow a fuse. We were working together so if we saw any smoke we could de-enrgize the circuit fast. We also had a fire extinguisher handy just in case. Please be careful...we don't want to lose any more sharks. Good luck.
John