Okay I have been trying to fix the wipers on my 80 and it seems that the relay (the one located in the jack compartment) is bad. Finding a replacement is almost impossible and when you find them they are $250 used.
Has anyone found a fix other than replacing that peticular part? I don't care if the intermittent feature works just want the wipers to work in low and high if for no other reason so that the car will pass inspection.
Some electrical guru could make a fortune if they came up with a fix for this problem.

Kona

 

Rain-X. 5 bucks a bottle. And when did it last rain around here anyhow?

Inspection? What inspection? It's an antique!!! Change your registration.

 

hasn't rained up here in weeks. but antique plates are the way to go. no inspection, registration is good until '08, and no stickers in the windshield.

 

How does that work?!? My '79 is a "nice weather daily driver", and as it's not rained here in about 3 weeks we've had a lot of nice, non-rainy driving days. Are there any restrictions on driving with that kind of registration?

 

I think you can only use the car for parades and going to shows. Somebody chime in and correct me if I'm wrong. Also I don't think you can personalize them.

Kona

 

Not sure about Texas, but here in Illinois you are only aloowed to drive it to car shows, and the all encompassing "test drives"
No one has ever stopped me even when they know I'm going to my office

Don

 

Technically, this is correct. But I don't know of anyone who's ever been stopped for this violation...and I've been on the forum for 3 years now.

 

The man's problem is fixing his wipers, not rainex, which IS a good product BTW....

at any rate he needs take the relay apart and look/find the coil, which is 12 volts, and then the contacts, should be no more than 3 to make anything work in a wiper circuit....
and then go to Radio Shack OR, a parts house and get a generic relay with heavy enough contacts read ten amps into that, to run the wiper.....wire it in and case closed....

GENE

 

Gene thanks for the advice. I found a GM wiper relay that appears to match the one I have except it does not come with the circuit board. Looks like the mounting pins are the same so hopefully I can remove the old one and solder in the new one.
If not you can bet I will take your advice and repair the old one. Thanks again.

Kona

 

OH Christ, they burried some circuit board in that relay??

Good assed freaking LUCK, no wonder they want super bux,
hate to say this, but you need do a junkyard search and get smart with electronics or you just got screwed without benefit of intercourse....

I can maybe help you if you can use a soldering iron and a schematic for something that should work, but nothing is a plug in on a 30 some odd year old car.....

as the years go by...the C4s will be further in trouble for just those reasons....electronicus crappicus....

GENE

 

Don't worry, Kona and I are neighbors. I'm just yanking his chain.

But it's beginning to sound like I was right in the first place...Rain-X

 

Gene, I'm pretty good with a soldering iron so send on any suggestions you have. Like I said in an earlier reply I am going to try to remove the old relay from the board and solder in a new one that looks like a perfect match but it's always good to have a backup plan.

Thank's Kona

 

Kona,
I managed to fix my 80's relay with a lot of patience and much swearing- took me ages to work out what replacement transistors to use, because I had to work out how it actually functioned first. BUT, it all works ok now.

Perhaps if you can tell me a bit about what it's doing, or not doing, then I can point you in the right direction for replacement components.
Have to say, relays don't often go bad (you never know though) so chances are the problem lies with one of the transistors that drives the relay. Does the relay click at all when you switch the wipers on?

I knocked up a wiring diagram for it too, but I'm not totally sure where it's saved on my computer at the moment! I'll try and dig it up for you.

 

The relay clicks when the wipers are turned off and on. It's very possible the relay is bad because I did a really DUMB AZZZZ thing which probably caused the problem.
I did alittle welding on my exhaust manifold w/o undoing the battery cable and that caused a short in the choke relay and the choke thermostat which I have already taken care of. I found a GM relay at the local parts house with the same mounting configeration as the one on the circuit board and I thought I would try swapping and see if that worked.
If you can find that diagram please post it just in case swapping relays doesn't do the job.

Thank's Kona

 

Hey,
If the relay is clicking, it's pretty unlikely that there's anything wrong with it - it's quite hard to blow up a heavily built thing like a relay, whereas it's much more likely that one of the delicate electronic components was damaged. My wipers would not work, even though the relay clicked, and the problem was in the circuit, rather than at the relay. I wouldn't replace the relay just yet - I might be wrong but it would be my gut feeling that it's perfectly ok if its clicking. By the way, it's a "normally closed" (NC) type of relay on that board, and it only clicks open when you put the switch to "delay" -- at all other positions, the full wiper motor current passes through the closed relay. Switch to "delay" and the relay opens, and intermittent current is passed through the big power transistor on the board (the one with a big ally heat sink strapped to it) - on mine it was this one that was shot.

Do your wipers just not work at all then? Or is it just the intermittent function?
To check the power, disconnect the wiper multiplug and prob it with the voltmeter, you should have 12v at the white wire (middle of the plug) at ALL switch positions, as long as the key is "On/Acc"
The purple wire (top of the plug) should be grounded through the switch, when ever the switch is in any of the running positions. The system works by providing a ground, through the controller board, to trip a second relay that's inside the wiper motor cover.
If no juice/ground, then it's probably a continuity problem either at the board or at the switch. Given that the board is bumping around in the jack box, chances are any wire break/cold solder joint will be at the controller, not the switch. Those switches are pretty simple and foolproof.

Hope that helps for the moment!

 

The relay still clicks in all positions. I have no wipers in any position so I'm afraid the circuit board is gone. They had a new old stock on ebay with a buy it now price of $350 OUCH.
Rain-X starting to look pretty good. I was looking through the Corvette America catalog and noticed they carry a " wiper pulse relay bypass jumper" I'm going to give them a call and see if this is something that will do just that Bypass the relay.
I will let you know what I find out.

Kona

 

Okay I think I have GREAT news. I talked to Corvette America and they have a wiper pulse override. It is part number 29570 and is $10.00.
It allows you to use a relay w/o the circuit board ,you won't have the pulse feature but it will get your wipers up and running.
$10 vs $350 easy choice.

Kona

 

It's probably still quite fixable - don't give up on it yet!
Have you tried those voltage/ground tests I mentioned in my last post? That's what you need to do to actually narrow down exactly where the problem is. Personally, I'd try those before using the ten buck quick fix - I'm not totally sure how this "jumper" works, but it's certainly possible that if you don't sort out the underlying problem, then the wipers still won't work even with the jumper connected...

Are you sure the motor's ok??

 

I used the testing procedure you suggested and the motor is good. I am going to take alook at the relay again this time with a buddy of mine who is very good at working with electrical.
Congrats on getting the Olympics and thanks for all your help.

Kona

 

Hey
Thanks! Got a few years to wait until the actual event though!

Well, best of luck with it. If I can help you further any time soon, let me know.

Cheers