On my C3 (1980), my windshield wipers work one speed only ... windshield wiper fluid pump works fine also, but when I adjust the pulse ****, nothing happens .....

Bad Switch or something else ???

 

In the rear compartment there is a pulse relay. It is bad, and not available at this time.

 

The tool storage compartment or battery compartment? And are you telling me that replacements cannot be found?

 

Tool storage. Your only venue is disassembly and replacement of the parts.

 

This unit here. Mine is 81, should be the same.

 

Thanks - I am still little confused ..... what is it that you are referring to in the pic & if I decide to "disassemble & replace", what is it that I need?

 

All the parts on the circuit board.

I believe the best thing to do at this point is let it go . Pulse wipers not working is not a huge deal. At least to me,but mine works.

 

The unit shown here in not the wiper delay, thats the alarm module shown. There could be many reasons why the delay does not work.

The wiper switch could be bad.
The park switch in the wiper motor cover could be worn out.
Bad ground in the wiper system
The delay controller module could have a failure, shorted transistor,bad voltage reguator diode, bad IC.

 

Sorry, wrong pic.

As stated above,(sorry), the 1 at left is alarm. The middle is the power antennae relay. The one on the right is the wiper pulse controller.

 

FYI if your relay should go completely out you can get a bypass jumper from lectriclimited which will enable you to restore slow and fast speeds.
I recently found a NOS switch on Ebay but the guy wanted (are you sitting down?) $450.00 OUCH. Bypass jumper was about $20.00

Kona

 

Are there ways to narrow it down, or is it just a guessing game and start swapping parts?

 

Switch or Pulse control?

 

I had the same problem with my '79, no delay function. I had a bad wiper pulse relay, mine was located in the center console, under the radio area. I was able to find one right here on the forum. Try posting a WTB in the parts section, someone else may be parting out a car and have what you need.
May the force be with you!

 

Now you know what I know.

 

Disconnect the wiper controller in the back of the car.
Using a multi-meter on ohms measure the resistance between the green wire and the black wire. This should be less than 10 ohms on all settings other than the delay setting where it should be infinity or open circuit.

while on the delay setting measure the resistance between the brown wire and white/black stipe wire. turn the delay **** the resistance should change from very high 1.5 megohms to very low zero as you adjust the ****.

measure the resistance between the black wire and the - battery terminal. should be close to zero ohms, less than 5

Disconnect the single pink wire coming from the wiper motor cover. With the wipers running use your meter check the resistance between the pink wire and ground. This reading should be very high until the wipers are close to the bottom of the windshield then the resistance should drop to 330 ohms for a very short time. In fact you may not even be able to read the value, just look for a change.

An other test is to quickly touch the harness end of the pink wire to ground while on the delay setting. If every thing else in the circuit is functional the wipers should stop.

Take the delay controller out and try it in another vette of the same year. Or you can send it to me and I will test and repair it for you.


Cheers
Dale

 

Pulse control. Kona

 

You guys are great and I now excited to GO IN Will let you know what I find.

 

see this thread
http://forums.corvetteforum.com/show....php?t=1562438


Dale

 

I have found the following so far:

Switch Position Center lead @ wiper motor (with test light)
Top/High speed ON
2nd/Low speed ON
3rd/Delay???? OFF
4th/Park??? ON

Replace BAD switch or maybe still a problem with transistor on controller board??????

 

Your results point to a problem with the controller board, however, there must be something else also wrong.

You said that you only have slow speed, repairing the controller board will not solve the high speed issue. That is a problem with the motor, wiring, or switch. In a previous post there is a link on how to test a wiper motor. To test the switch disconnect the wiper motor and use a multimeter to test resistance to ground on the upper and lower motor harness connections with the switch in low and high. In low both gray and purple should have no resistance to ground. In high purple should have no resistance and gray should have very high (infinite) resistance.