72 wiper door

[Monte M.]

Re: 72 wiper door

Keith,
The fact that removing the wiper fuse from the fuse box does nothing, says a lot.
First, like you said, check every fuse, but also check any wires that are plugged into the box too.
Then I would go back out to the engine side and unplug every plug to see what changes. If you unplug the wires to the switch we were talking about that is on the firewall. Check everything you can find.
If you can, take a high resolution picture of you wiring harness. Send it directly to me. That way it is not too big for the site.
Where are you located?
Do you have a good wiring diagram? If not I can send you one.
Now, it is figuring out where the splice is. We will, just like we got the headlights.
We will do the wiper vacuum as soon as we are done with this. That is pretty simple.
Maybe Terry can chime in about the difference in early 72 wiper motors (Aug 71) and later ones like mine (April 72).
Monte

[Keith L.]

Re: 72 wiper door

Monte, pulling the wiper fuse killed the power. I unplugged the three wire plug to wiper motor and it killed power to the red wire so no power is coming into the switch that allows power to flow when door is up. If I understand correctly the power originates in the red wire and goes through the button switch after the door raises and goes to the wiper switch. Is that correct? The wire diagram I have is not very good in my opinion. I won't be back to the car till Monday as I am going out of town. I am concerned that the black plug has power on it. Even when the switch is off.

[Monte M.]

Re: 72 wiper door

Keith,
Edit;;;;;

I missled you, the switch on the firewall should be shutting the red wire that goes into the back right of the motor.

[Keith L.]

Re: 72 wiper door

What In saw in mine is the big red wire in the harness come out and has a plug with two terminals that one goes into the button switch and the wire coming out of the button switch goes into the other side of the plug witch then goes to a plug that has another red wire pluged into it that goes into the wiper motor. I don't know how it turns into a blue wire. So where does the power originate and where does it go from there?

[Monte M.]

Re: 72 wiper door

Keith,

Sorry, I mislead you. You are correct. I will start from the wiper motor. as the wire comes out of the wiper motor it goes to the switch on the firewall. If that switch is being depressed, the wiper should not work.

If you unplug the red wire from the wiper motor, do the wipers still work?

If you can get the switch to turn that power on and off, we just need to follow it back to power.
Forget the light blue wire I was talking about before.
The other end of the red wire should go to the twist override switch under the dash. So, check and see if turning the override switch under the dash cuts the power off to the red wire on the wiper motor.If it does, we can take it from there. If it does not, or is not tied in at all, we will have to figure out what else is going on.

That wire basically starts at the ignition. It then goes to the override switch under the dash. From there it goes to the switch on the firewall and then heads to the wire motor. Let me know how that turns out.

Monte

[Keith L.]

Re: 72 wiper door

OK I see it now on the wiring diagram from the switch to the override to the button switch on firewall and then to motor. I have power on the two of the three wires on the three wire plug when the red wire is unplugged.So I have to be getting power on the other side somewhere. I guess I don't understand how the bypass switch works. I understand the vacuum part. But does it also turn o n the power? If it does how does the power get there if you don't use the bypass? Sorry for this being so hard for me to understand.

[Keith L.]

Re: 72 wiper door

One thing I see one the wiring diagram if I am reading it right is the vacuum solenoid behind the tach. Mine has a blue on one terminal and two yellow on the other. The diagram appears to only have one yellow. Is it supposed to have two yellow of is that another power source?

[Monte M.]

Re: 72 wiper door

Keith,
This is not much, but at least we can both be looking at the same diagram.

[Monte M.]

Re: 72 wiper door

Keith,
you have two power sources to the wipers. The one is the red wire that goes to the back/side. we are not worried about that one right now.
The yellow is the other power source. It should not be getting power until the wiper door is open. Behind the drivers dash, close to the bottom, there is a relay that has two vacuum hoses going in it. It appears that this is now the problem. It is allowing juice to go through when it should not be.

Once we get that back on line we should have it. I have an NOS one around here somewhere. I will post a picture of it. Or maybe someone else can post it. I will go lok for it right now.
Monte

[Keith L.]

Re: 72 wiper door

are you talking about this http://willcoxcorvette.com/advanced_...words=solenoid

[Monte M.]

Re: 72 wiper door

Keith,
I am working off of twenty five years of memory here, but I think this is the culprit. Vacuum from the vacuum system opens and closes this turning on and off the electrical power.
My guess is there is not one of these at all.
With the problems you have, if you remove this relay all together, it gives you a set of problems very similar to your vacuum problems and your electrical.
I HOPE. we are on the right track though.

If I remember right, it sits in a sprung "U" clip that is attached to the lower portion of the back side of the drivers side dash. Maybe someone out there has a picture of one. I have one somewhere, but I do not know if I can find it.

[Keith L.]

Re: 72 wiper door

Or is this it, and where on the car is this? http://willcoxcorvette.com/product_i...ducts_id=12836

[Keith L.]

Re: 72 wiper door

I have that. I thought it was the other way around. That the electric current controlled the vacuum as opposed to the vacuum controlling the current. Otherwise what would turn the vacuum on when you turn the wipers on? I need to rest my brain. I may go by and have a quick look tomorrow before I go out of town.

[Monte M.]

Re: 72 wiper door

I will go out and double check some of the circuits. To find out if they are normally hot, cold,whatever. That way we can start whittling away at each wire as we go.
There is not the switch on the firewall in this diagram. There is still one thing not making much sense to me. I am going to go double check a few things on my car before I send you on any more wild goose chases.
Things like that red wire should not be hot unless the override switch is turned on.

You asked about the override switch. It is under the dash, right between the two vacuum overrides. It twists one was to send power and the other to stop it. It is for changing your wiper blades. You override the wirer door so it is up, then you turn the round knob until the wipers come up far enough to be ableto change the blades, then you turn it to stop the blades while they are up.

This switch by itself could be causing a ton of these issues. I was not aware you were not aware of it. SURPRISE SURPRISE. There is always something more to the cars to surprise you.

While I was looking for that relay I posted a picture of, I found two NOS fan switches I did not know I had.

I was hoping to head to Lake Tahoe for the NCRS meet this weekend, but I could not get out of work. VERY BUMED

[Keith L.]

Re: 72 wiper door

http://willcoxcorvette.com/instructi...-72_5_2009.pdf
This was very informative reading. I have two seperate systems. I can turn them on with the under dash cutoff and the safty button switch on firewall works. and the ignition does not even have to be on. With ignition switch on if i turn off the under dash knob I can turn them on with the wiper switch but the power does not go through the button safty switch on firewall. I just got to find where it is getting power with the under dash knob off.
Where is the relay? I found one behind the tach high but it only has 4 wires. The Willcox paper shows 5 wires. Am I looking at the right one? It is above the vacuum solinoid. behind the tach.