Can anyone explain the proper operation of the wiper switch and the three switches under the steering collumn? I have looked at three and all are different.
thabnks RDR
thabnks RDR
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Re: 68 wipers
If you have an operators manual, it will explain them all. There are two vaccum over ride switches under the column. One controls the headlights and the other the wiper door.
The electrical switch has to do with the wipers and to tell you the truth, I forgot how it works. It has been too many years since I had my car back together But, I think has to do with the wiper motor.
The switch above the center instruments controls the wiper speed and washers. It should have 2 position only in 68 and later years had 3 positions (as I recall, I could be wrong. Look at your owners manual because it discusses all this in detail. Terry -
Re: 68 wipers
Yes, Terry is correct. Two vacuum override switches and one wiper override switch under the dash. One of the vacuum switches will allow you raise the headlight doors without turning on the headlights (for cleaning or repair) and the other will allow you to raise the wiper door without turning on the wipers. The electrical override switch with a chrome knob will allow you to stop the wipers in the middle of their operation (such as to clean or replace the blades).
Theoretically, the limit switches, etc., should allow the wipers to come to a full rest in the windshield cowl before the wiper door closes, but this doesn't always works correctly, so sometimes I will use the override switch to raise the door, then turn the wipers on and off, and then when they have come to a full rest in the cowl, I will then use the override switch to lower the wiper door. Not how it's supposed to be but it's better than risking bending wiper arms, etc.Comment
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Re: 68 wipers
Thanks I will see if I can figure it out.
RonnieComment
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Re: 68 wipers
If you are having bad troubles let me know. After looking at the vacuum system you need to make sure there are no vacuum leaks, make sure all the electrical switches are good. The two most important switches are the micro switch mounted on the fire wall and the vacuum solinoid switch behind the dash. The wiper and the headlight system should best be looked at together and not seperately. It needs to be perfect to function properly. An assembly manual is a great place to start. It will tell you how to set up your vacuum canister and the micro switch, etc. I have some trouble shooting material if you need it. TerryComment
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Re: 68 wipers
Thanks for your help, I think starting with a car some one had monkeyed with is the bigest problem. I think the under dash wire was from a 69 or later and we had a couple of extra wires. We replaced this wire and now have everything working. I did not know the head light switch was there. I think i have it correct now. thanks again.
RDRComment
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Re: 68 wipers
Vantastic! Those things can be a big mess to deal with. I have a set of dealer tech bulletins and some other stuff pertaining to the wiper doors and headlights. It seems that when the car came out, not even the service manual could be reliable to reference for repairing the system??? TerryComment
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Re: 68 wipers
The switch with the knob is a single wire switch and it breaks the ground of the wiper motor when turned to the left.
BryanComment
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Re: 68 wipers
This applies to my original owner 68's wiper switch. Discovered many years ago that when the car was parked and not being used that if the windshield wiper switch was accidently turned on and turned off that something was activated and the battery would be dead in a few days. From that learning experience, whenever the wiper switch is accidently turned on I start the car and properly cycle the windshield wipers to off. Cleaning the dash or inside windshield sometimes the windshield switch would get activated acccidently.Comment
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68 and up wipers
You are lucky the battery went dead. Doing what you describe on a 1968, or shutting off the car while the wipers are on the windshield (not parked) on any 1968-1972 leaves the wiper motor energized. More than one early C3 has caught fire under these circumstances. This was one of our stronger points in favor of judging points for the battery cut-off switch.TerryComment
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Re: 68 and up wipers
Thought this might be only with the 68's and that the problem would of been corrected later in the model year, mine is a February built. I am going to check out my original owner 70 one day with a volt-meter and see if activating the wiper switch only will draw current with the key off like the 68.Comment
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Re: 68 wipers
Bryan, the wiper override switch on my '68 pulls straight down. It doesn't turn to the left or the right. I guess it's possible my switch replaced by the prior owner at some point.Comment
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Re: 68 and up wipers
The 1968 wiper motor is a one-year only item, I believe, in part as an effort to correct this issue, but some form of the problem or a similar problem persisted at least to 1972 and I suspect beyond that. I have not made an effort to track the circuit that provides power to the relays and/or resistors under the motor/pump cover -- I can tell you in judging I have observed a large number of deformed covers due to something underneath heating the cover. I have also observed about half dozen burned Corvettes in which the fire appeared to start in the wiper motor area -- and in all cases the wipers were on the windshield and the car caught fire while parked with the keys removed.
I think the simple solution is to disconnect the battery when the vehicle is parked.TerryComment
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Re: 68 wipers
Michael,
I'm talking about the wiper service switch. It is mounted on the same bracket along with the vacuum pull down switches. This switch is used to stop the wiper blades for servicing.
BryanComment
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Re: 68 and up wipers
Here is the 68 wiper motor wiring diagram. As you can see, the red wire going to the wiper motor is connected ahead of the ignition switch making it hot all the time to the latch relay in the wiper motor. That's why it is important to have the wipers cycled thru to be in the proper off condition.
Bryan
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