My wipers stopped working the other day. The door still opens, but the wipers don't move. I tested the connector and have power to the two outside terminals, but am not reading power or ground to the middle one. Any thoughts?

 

I think I have the same problem, mine will work for one use, but if you try again 10 secs later, no go. I think it has to do with the switch, this operates as an earth continuity, so it may be worn. I am doing mine tomorrow, as it's a holiday over here. Let you know what I found out.

 

The center wire (yellow) should have power when you turn the key on.
Is the case grounded?

 

The center one should have power, the others are ground. One is hi speed, the other is park. When both are grounded the wiper goes into low speed. Most of the times when the motor starts working it's a case grounding issue. Some have a ground under one of the mounting bushings sleeves. If that's corroded the wipers won't work.

 

There should never be power on the outer two connectors at the motor. The yellow is hot, the green and blue wires are your field grounds.

If you have power on the one or more wires and this suddenly happened I would check the wiper motor relay to see if it shorted out. Go to this page it will show you!

http://willcoxcorvette.com/repairand...elp.php?hID=95

Green to Ground is high speed and jumping green to blue should give you low speed. When you remove both the green and the blue wire grounds the motors on 1969-1972 will park automatically.

There is also a ground wire that runs from the case terminal to the blower motor connection on the car. Make sure this is a good ground! Check the page out, you should be able to figure out what is causing this.

Also check the center gauge cluster ground on the back of the cluster. There is a terminal there that grounds the gauges and the wiper switch. If this ground is off it can cause back feed voltage.

One thing everyone forgets too! If your dash cluster is broke in half at the thin area and the two halves are not touching you will loose your ground on your wiper switch. The wiper switch plate screws to the top of the dash cluster bezel and when the tiny area breaks it will loose the ground. The simple way to fix this is to make a jumper wire from the wiper plate to the ground terminal.

Willcox Inc.

 

I spent a couple days messing with my wiper motor and I think that the center is hot at all times

Years on the motors might make a difference but on my 69 the middle terminals conect and share the same post connection on the motor so if the heavy red wire is hot all the time the yellow wire is the same.

My problem ended up that the wiper switch needed to be grounded to make the whole thing work (I had the dash all apart because of a restoration )

 

Fonz,

You are correct!

On cars from 1963-1967 and 1969-1982 the center is hot all the time! 1968 cars are the worst to figure out but we have detailed instructions on how to test this motor on our site.

Willcox Inc.

 

Fixing to check out my dead wiping on this '75.
Lots of fun driving home wednesday in a thick wet fog!
Although, if the truth be known, most of the dash was laying where the shift console should have been and the wiper control was on the coffee table in the den at the time......

 

I just finished adding a ground wire to wiper motor, now they work fine. My wipers did not work after I took my car out of winter storage.

 

What if you 12v switched coming from the open switch is not 12v? Mine is only reading 2.9v. I can jump it w my power probe and things work fine. It "was" working, but now nothing. Can the wiper door open trigger switch reduce power and not go bad completely?

 

The middle wire should have 12 volts at the motor at all times. Are you saying you don't have it? If so I'd be worried about why vs. jumping power to the motor. You can test the motor by going to our site and looking up the appropriate video or use the tech pictures page.. both have links to testing.

Willcox