Hello all,
I've got a question about the wiper switch and the vent assembly that it bolts to in a 70 coupe. I'm trying to diagnose why my wipers quit. The wipers quit some time ago and since I've got everything apart, I'm trying to fix them now. Does the switch and the vent assembly that it bolts too seek ground through the center gauge bezel when it's all bolted up? The reason I ask is because when I'm holding the assembly with the ignition on, I can only get the wiper relay to function when I ground the assembly onto the metal bar that the wiper relay is bolted to. I also get a pretty good shock. But I can run the switch through the settings and the relay responds. As soon as I remove the assembly from the good metal ground bar, I get nothing from the relay, and thankfully, no more shocking. I've followed the Willcox diagram and tested the ground that goes to the relay in the triple plug while unplugged from the relay. This ground wire is solid black. It is a good ground. The other ground from the relay(atleast I think it's a ground) that goes from the triple plug to the wiper plug is black with a white stripe. That ground doesn't seem to be good when testing it unplugged from the wiper switch. I get nothing when testing it with a volt meter and a known 12v live source. In the Willcox diagram I see that he states that the wiper switch must be grounded. Am I missing a ground wire from the wiper switch? This seems wrong to me and dangerous. Any thoughts? I've included a pic in hopes to make sense of what I've stated above. You can see the metal bar I'm using to ground the assembly on in the background near my thumb.
Thanks!!

 

You're not missing a ground wire per say, the wiper switch bezel gets it's ground through the gauge bezel not a wire. If the gauge bezel is broken you lose the ground.

Have you tested the motor using Willcox's troubleshooting video? That should be your first step.

http://www.youtube.com/watch?v=ERTtTH8DoCE

 

Thanks DZRICK,
So it grounds at the center gauge bezel? What does the bezel ground to? It doesn't seem to be anything substantial.
Yes, I've done the troubleshooting. My wiper motor is failing. But Bubba's been all over my car and his fingerprints are on the wiper wiring. I'm testing things to make sure they are correct. I'm confused what wire triggers the wiper relay. I'm getting 12v constant to the wiper solenoid on the back of the tach. Shouldn't that only be energized when the switch is on? Or is it the a ground that activates the solenoid and therefore there is always power on the hot side of the solenoid switch? Just stuff like this that I need to get straight before I button up my dash.
Thanks for the response!

 

I've got a '68 and the wiper motor switching is done through the ground. That is NOT the case with the 69'-up.

Honestly I can't answer your question about the solenoid. Off the top of my head, I can't remember if the solenoid is vacuum operated and makes or breaks the power or if it's the other way around.

If you've bench tested your motor and it is bad I'd get a new one, bench test it and if it passes install it. Ground the switch even if it means running a separate wire. You may find that everything works at that point. If not maybe we can get Ernie and Roger to come out from hiding.

Ernie and Roger are the wiper motor gurus here, I know they want to hand the torch off but...

BTW, yes the gauge bezel has a ground wire, when everything is put together the wiper switch gets it's ground from the bezel as long as the bezel isn't broken. If it is broke you'll need a jumper wire to get a ground to the switch.

 

Thanks DZRICK,
I will make a ground wire because I see no ground for the bezel at all.
Thanks for the info!

 

The bezel ground is there its just hiding. The ground for the bezel is the 14 gauge black going to the temp gauge.
Ground for the wiper switch comes through the bezel housing,if yours is broken you might have to connect the 2 bezel pieces with a wire.

 

Zap.. been there... felt that...

His bezel is broken and thus he is losing his ground. Looking at the wiper switch plate I see the upper portion of the center bezel but no lower.

Run a jumper wire from the screw that holds the switch to the bezel plate down to one of the screws that holds the small gauges in the center dash bezel and your shock should go away..

Willcox

Oh.. Hey Roger and Rick.. Been a bit busy the last few weeks.. I'll be back soon.

 

Hi guys,
Thanks for all the help!

I ran the ground wire and things are working well.
The solenoid on the tach was confusing me because I could feel it trip now that the switch is properly grounded, but I was still able to blow air through it. So I figured it was bad. Well, I plugged the filter port with my finger and bam! No air. Turned the wiper switch to Off and with my finger still on the filter port of the solenoid, I could blow air through it. So I'll plug the filter port with a vacuum cap and I'm good!
Thanks again guys!!

 

See, just mention their names and they come running to help!

Roger and Ernie have helped so many of us figure out these wiper motors and the wiring that is supposed to make them work it's not funny. Quite an asset to the forum!

 

Thanks Rick, just chimed in to back you up,you had it under control.

 

I'm thinking aloud here Roger...

It's time to pass the torch! Rick's has it under control now and just keep in mind Rick, without your input the 68's would still be wondering where that damn black wire went...

 

I remember that damn black wire a whole lot different than you guys seem to.

I was just the guy with the '68 with his dash apart and a non-working wiper motor.

Of course, I'll help as much as I can but without you and Roger that torch is just going to burn my fingers!