Windshield Wipers

[Bob Chadwick]

Can someone explain to me the mechanics of the windshield wipers system? Mine are not working.

I have the dash apart with the vaccum to the headlight switch open. Could this be the problem; no vacuum to the circuit? It appears from what I looked at this is a seperate source.

Bob

 

[RalleyRed]

Bob,

I can't tell you how it works as I've been trying to figure my brothers 69 out for quite some time.
But I do know that it is all related, same source, and even tied in together. The headlight swich, override switches under the steering wheel, there's a switch on the back of the tach and everything under the hood.

There are some thing's that changed from year to year ( more $hit added in most case's)

I'm sure someone else will be more helpful, good luck.

Rick

 

[Bob Chadwick]

Rick,

I took a look at an electrical book I've got and had a revelation; the wipers are electrical and not vacuum. (I don't know why I thought they were vacuum operated).

I've got the headlight switch out with the driver's sdie of the dash. I've also noticed that the turn signal lights in the car aren't blinking, though they are working at the four corners of the car.

I'm assuming that the headlight switch is tied into all this, though I am not sure. I just had some electrical work done and don't want to put the dash back together only to take it apart again.

Hopefully someone will be able to shed some light on the subject.

Bob

 

[RalleyRed]

Bob,

I didn't even notice that your vette wan't in the 68- 72 range.
When you said the blinker's weren't working you meant the indicator's in the dash right? Is everything else working?

I'm an electrician, but I hate working on a cars system. No room!
I do have vaccum operated wiper's on mine and my machanic couldn't get them working. So after trying many times and buying a new wiper motor, I forgot to turn the key off before unhooking the motor pulled the ground wire off and the damn thing started working.
Now my thought is if it ain't broke don't fix it.
I will attack it again the next time I HAVE to pull the dash pad off.
Again I hope you find your problem, it makes driving these toy's so much more fun when everything works right.

Rick
By the way I think your going to find a bad ground

 

[69MyWay]

Bob,

The wipers on the 77 are not that complicated. There are three main wires on the wiper motor. One is the main source of 12+ ignition on power. The other two are signals for high and low speed. The wiper has to be grounded. Your switch in the dash has to be grounded.

So, unless the wiper motor is bad, you have two main things to look at. Makes sure that the switch is good, and that it has a good source of ground. On the wiper, you will see that there is a fourth wire hooked to a metal tab that is attached to one of the housing screws. Follow this wire to ground. It really does not matter if you ground it to the block or frame as long as it is tied back to full chassis ground.

The washer circuit makes up the other wires that you see. This is all part of what is on the very front of the wiper housing cover. When you request washer, your switch grounds out the wire you see on the cover which also has a 12+ ignition wire that jumps right off the main 12+ wire going to the motor.

So, check your grounds, check your fuses, and you should be up and running. If the motor is bad, you can get a new one at Autozone, etc. for about $50.

A bad blinker is again either a bad ground or bad blinker bulb. You should go out on the car at each corner where the lights are, trace the wires back to the light chassis ground and clean, retighten those grounds. You also have a ground in the interior up on the A pillar kind of next to the wiper switch on the metal part of the inner body. That one could be loose. One way to know is if that ground is bad you won't be able to turn on the interior lights from the light switch.

Good luck. Vigman is the reall expert in this department. I learn by trial and error. He can give you actuall schematic color charts and wire numbers.

 

[Bob Chadwick]

Thanks Guys. The ground definitely explains the turn signal indicator bulbs. I forgot that they ground through the tach and speedo which are not in the car at this point and because of this the ground is not connected.

The wiper switch is on the turn signal stalk in my car. Perhaps the ground is here as well.

I'm probably just being overly concerned but I do not want to put the left side driver panel in and have to take it apart again.

Bob

 

[vigman]

Confused?????

Ok turn signals first....

When you click the turn signal.. do the lights for the turn signals ( on the outside of the car) come on & stay on?

The Flasher is a crude but functional device, it needs the current draw of ALL the bulbs to flash.

You have a HEAT driven relay for the flasher.

When you engage the switch you supply current to 3 bulbs, which in turn heats up a bi-metal contact in the flasher. When it gets to hot, it moves & opens when it cools it closes

Blink,Blink,Blink.

So if the some of the lights come on it dosen't draw enough to open the circut.

No blink

If none of em come on you might have a bad switch, bad flasher, blown fuse, no ground
( or any combo platter of the above )

Need more info to proceed.

Mike

 

[vigman]

And now wiper

Chris ( as usual ) has got it knocked......

You need to check the following..

The 3 wires in the wiper switch connector

Dark Blue
Black/White
Light blue

The 2 blues are Hi & low speed
The Black/White is a switched ground.

The ground ( looks like ) it's generated from the frame of the switch.

You have to have the switch mechanically grounded for things to work.

The yellow wire on the wiper motor should +12 with the key on.

So to test Ground the Dark Blue and you should be wipin away.

Note ( 73 wiring diagram )

Mike

 

[Bob Chadwick]

Mike,

The four lights on the corner of the car are working. The interior lights are not in the speedo and tach so they are not grounded. I'm almost certain that they will work once put into the proper instruments and grounded.

Will the grounding of the tach and speedo give me the ground on the windshield wipers or are they grounded elsewhere?

Bob

 

[vigman]

Not 100% sure on yours

But ( guessing here)

The wiper switch ( being on the stalk ) is different than earlier models ( BUT ) since GM is lazy I'll bet the colors/functions are the same.

Do you have an Ohm meter handy?

Maybe some clip leads?

We could do a bit -O- testin'

I'll bet even money that the column ground is working, it the wheel just hanging or bolted up?

Mike

 

[vigman]

More turn clarity

You click the left turn
( key on, running light's off)
and exactly what light's up ?


AND

exactly the same for the right?


Do your emergency flashers work?


Mike

 

[Bob Chadwick]

You turn on the left signal, the left exterior lights come on, you turn on the left and the left lights come on, you turn on the flashers and all four come on. This, of course, does not include the interior lights.

I have the steering wheel hanging from the two bolts, without having tightened them as of yet.

I'll need to take a look at these things the next warm day here in Atlanta.

Thanks for all your help.

Bob

 

[Bob Chadwick]

Much griping, time and beers later, voila, the windshield wipers are working again. And boy do I feel stupid. Of course they can't work if you knock the connector off the back of the wiper motor. ;stupid

The next wiper question. Sometimes they run into each other and bind up. Any body know how to adjust them so this doesn't happen?

Bob

 

[69MyWay]

Much griping, time and beers later, voila, the windshield wipers are working again. And boy do I feel stupid. Of course they can't work if you knock the connector off the back of the wiper motor. ;stupid

The next wiper question. Sometimes they run into each other and bind up. Any body know how to adjust them so this doesn't happen?

Bob

:L :L I needed that this morning! So, I am not the only one. Trust me, I am the kind of guy that will replace a bulb in the ceiling of the bedroom only to find out the new one does not work either until we turn the switch on!

Wipers are very simple to adjust. First, soak with penatrating oil. Look at the point where the wiper motors goes through the firewall into the cowl area. You will see where the right and left transmission arms come off the rotating shaft. There are like 10mm nuts there. You can loosen those, and slide the transmission arm back and forth to affect an adjustment on how far the arm travels, etc. Please soak it in some oil first, because if you twist that nut and wring off the stud, you will be back to inop wipers.

 

[Bob Chadwick]

Thanks Chris.

 

[Guy]

The next wiper question. Sometimes they run into each other and bind up. Any body know how to adjust them so this doesn't happen?

Bob

Mine bound up once and I was told a simple trick is to buy wippers that are 1 inch shorter than called for. Since it only happened once, I have not tried this yet.

Guy

 

[Bob Chadwick]

Guy,

I have a similiar problem except mine only bind up when it rains.

I'll keep that in mind though I want to give a try at fixing it right first.

Bob

 

[Guy]

Guy,

I have a similiar problem except mine only bind up when it rains.

I'll keep that in mind though I want to give a try at fixing it right first.

Bob

Yup - They bound up after running most of the day on the way to Vettes at Carlisle last year.

Guy