I have a copy of the '68 schematic that you have provided to help with the wipers. My motor ***'y is out being rebuilt and I'm checking to make sure that the car is not also screwed up.
Question- As I'm checking the wiper sw connector for power, or not, you suggest putting the key to the #1 position (on?) and test that there is on power on any of the 3 pins for the wiper sw. I get power on the light blue side. You say that the power may be coming from the wiper relay. Are you refering to the one on the console? If so, this wire is part of the coil circuit and is getting power from the yellow wire that goes back to the center motor plug pin, and also powers the washer(?). I'm stumped- where does the power come from when the wiper motor is out of the car? (The wiring harness is new).
Any help would really be appreciated!!
Rand

 

Yes, the power on the blue wire can come from the wiper relay if the relay is wired wrong. This relay is located inside the shift console. If you uploaded the wire diagram please check to see if the wires on the relay are in the same position as pictured in the diagram.

If the center dash console is broken you may need to run a ground wire from the wiper switch to the back of the small gauge cluster. You should check this since lack of a ground can cause voltage to back feed on the light blue wire.

In almost all cases the issue with the light blue wire having power is a direct result from having a ground issue or a wire connection issue at the relay.

You should also verify that the ground wires on the relay are good! You can verify them by taking a known power source and clipping a test light on it. Then probe the black and black and white wires from the relay to see if they are grounded.

Once this is checked, and then you have checked the wiring on the on the relay go to the center dash cluster ground and make sure it’s working properly. It’s a single black wire that plugs in to the back of the center cluster. It’s not hard to reach especially if you yank out the right hand dash pad.

If that ground is good, inspect the center dash cluster bezel. In the thin area is it broken? If so, you will need to run a jumper ground from the switch to the back of the cluster.

Verify the motor ground as well. You can pick up 12 volts at the motor three wire connection to test with. Make sure the black wire that runs to the blower motor is a good ground.

Test these things, and if it still is not working email me direct at willcoxcustomerservice@willcoxcorvette.c om .

Willcox

 

Thanks so much! I'll give these a try.
I appreciate the feedback.
Randy

 

Now I think I figured out mine. In an earlier post I found a black wire that was broken by the ignition. It went to a black clip in the wiring harness. Is that the black wire, because I have power going to blue wire also.

 

The only ground I see is on the lower shifter console. Is there an upper console ground? Pics please.

 

Hey Budman,
I just decided to ground the heck out of everything. I added 5 behind the panel. That ought to do it.
Rand

 

On the back of the dash cluster there is a ground wire. If this wire is not plugged in you will have problems. The wiper switch is connected to the metal wiper switch plate which screws to the center dash bezel. The center dash bezel is the ground for the wiper switch.

This is why I say if the bezel is broken, you have to make a jumper ground from the wiper switch retaining screws to the back of the dash cluster.

This bezel is to be grounded by a black wire on the back of the cluster. There will be a terminal on the back side of the small gauge can. I think you can see this real easy if you remove the passenger side dash pad.

Willcox

 

Thanks Willcox,
My cluster does not have the terminal so I added a ground to one of the screws. This should work.
I appreciate the feedback.
Rand

 

Did you find the black ground wire for the cluster? There should be a terminal on the back for it to plug right in. Before you plug it in, make sure it is a grounded wire.

 

Hi Willcox,
Here's what drives me nuts... I bought this same car in '71 and later sold it. A few years ago I bought it again and some joyful person thought that it would be beneficial to society to whack up the wiring behind the meters when they installed their cassette. My job on the planet is to now fix this contribution.
If the wipers want ground, that's what I'll give them. (Can't wait for the motor to be returned from the rebuilder).
While we're on line, there is to be no +12 at any of the 3 terminals of the wiper sw connector when the ign sw is "on"?
Thanks
Rand

 

On the three wire connector at the wiper switch. . . There should never be any voltage! This system is a ground operated system with constant voltage to the wiper motor.

 

If I had smoke coming from the motor do you think I smoked it?

 

If you follow the (updated, we had a typo) test for the 1968 motor and it smokes, then I would say there is a good chance the motor is bad.

Is it smoking on all speeds or just one? When it smokes is it running?

If you test the motor and it works on either speed but not the other, you may have a field out on the motor or another problem.

 

Did I mention I hate 68 wiper issues! Hardest one of them all to figure out!

 

I'll try to test it tonight.