First I want to thank everyone who helped me out with this problem the last time I posted it. I took the wiper motor out of my '68 and sent it away to have it rebuilt. It came back in perfect condition and had been bench tested as good.
When I put it back in the car, I got the same situation that I had before I had it worked on. (which leads me to believe that the original problem wasnt the motor at all).
When I turn on the wiper switch on the dash, the wiper door opens but the wiper override light immediately comes on. The door seems to stick slightly at the top of its swing and then goes to full open. However at this point the wipers will not run. Even when I turn off the key the wiper override light stays on the dash and the only way I can get it to go out is disconnect the battery. Where should I look next?? It is a frustrating situation but isnt that what these older vettes are all about? Thanks in advance for any additional help

Frank

 

The o'ride light is supposed to come immediately on so far so goos there

start withthe simple

first check to see that the wiper door when open fully engages the microswitch,

then check the switch itself with an ohm meter

Next check the oride switch under the dash, make sure is is connected, and that it also works ( use ohm meter here as well)

finally check the wiper solenoid, and all the connections

problems beyond that would be ground related i would imagine,

but you could check the voltage at the connections to the motor in the switches various positions to help isolate the propblem


good luck



Tim

cheers

 

OK so where is the wiper soleniod??

I am having a simular problem.

 

Look on the firewall, upper pass side, above the heater box. Black plastic case, two red wires. Make sure the plunger is fully depressing the switch, You can hear it click, or check it with an ohmmeter

 

The wiper solenoid is behind the tachometer


the microswitch or limit switch is under the hood, like the man said above



cheers

 

Solenoid-sorry, kept thinking microswitch-too many of these

As Sweethence mentioned, the solenoid is behind the dash, mounted on the tach housing. On my 68 it's a grey color, two vacuum hoses, three ports(one is a vent) and a two wire connector. It is supposed to make electrical contact when it sees a vacuum signal to prevent the wipers from coming on before the wiper door is open. Have to take the speedo/tach cluster out to get to it

When I was having these problems, I found the **** under the dash wasn't grounded. Ran a separate ground and everything has worked fine since

 

Thanks again to all who replied. I have checked the micro switch and now I guess its on to the solenoid and I not looking forward to tearing the dash cluster out........Frank

 

My solenoid is just hanging down behind the dash.

 

If the door is opening, and the wipers are not working then go to the wiper limit switch located to the Passenger of the wiper motor.

There is a plunger that hits this switch when the wiper door opens. If the plunger is not hitting it hard enough, then you won’t get current to the wiper motor. If the limit switch is bad you can unplug it, and bypass with a single wire. This will tell you quickly if this is your problem.

The wire that runs to the limit switch is a large red wire with a white stripe.

If you find out the wiper limit switch is not bad, then go to the solenoid on the back of the tach. It is very rare for this to be bad!

The purpose of the solenoid is to prevent the motor from running if vacuum is not present in the wiper system. You can test the solenoid by powering it on one terminal with 12 volts, and ground the other side. When powered up it will click and also stop vacuum.

I hate to say it but many times customers have brought their cars in to the ship for the wipers not working and the only problem is the wiper override switch under the steering column is turned off.. So you might check this too. I pasted an image below. While the wiring for a 1968 and 69 is a little different, the system works in the same manner.

 

When the ignition is turn on, which wires get power? I get power to both outer terminals on the switch when the key is on.

 

Oh WOW what a surprise!!!!!!!!!!!!!!!!!ha ha ha before I tore into the instrument cluster to find the solenoid I decided to get a new dedicated ground to the motor and what do you know......the wipers worked. Now however I am having trouble with the wiper door hanging and not binding and not returning. Does anyone know the proper procedure to adjust this door linkage. Thanks again.

Frank

 

Ain't it when it's something as simple as that? The problem with my system, after tearing into things and burning up at least one motor turned out to be ground related, although in a different area.

As for the door binding up, maybe it's the system/linkage getting worn, hopefully someone that has dealt with that before can help