Intermittent wiper question
intermittent wiper control module which is mounted in front of the
compartment where the jack is located. Remove the storage tray and
you will see it. I replaced it several years ago and was able to purchase
one from my local chevy dealer. List price was about $250 but my dealer
discounted it to $200. Have also seen it listed in some corvette catalogs
such as Zip.
[Modified by mark79,80, 7:34 PM 9/18/2003]


I only ask 'cos i've been doing a bit of work to mine of late, and thought I might be able to help....
Hope you didn't have to go for the megabucks controller replacement!
I was shocked to this pop back up today, as you mention it is an older post. I actually have not had the chance to even look in the jack compartment to see what is even going on there. The weather here was perfect for going topless in the Vette back when I was asking about the wipers. This week has been a wet one and I wish I had gotten around to fixing them. It is an amazingly long way to grab that wiper control every 15 seconds or so. Maybe this weekend I will give the module a look over if I get the chance. I have a recording session on Sunday so it will have to be tomorrow if the wife and kiddo allow. I am all ears on any suggestions you may have.
I am assuming the first click up is intermittent with next click up being low. The top position would be high. Am I correct on this? Pushing down would be like what I would refer to as a "mist" function. Let me know if I am wrong on any of this. Right now my wipers operate in "low" in the first and second clicks up just so you have some background on what is going on with them.
Thanks for the check-up!
Dave
http://iotech.no/corvette/index.htm
I too, am an electrical idiot, so don't feel bad.
The Best of Corvette for Corvette Enthusiasts
he inspected the circut boards and found several bad solders on them due to age...resoldered them all and now they work great!
the best part is that the cost was zero! i tipped him enough to buy lunch and we were both happy guys!
I tested mine by staying in town and driving around in the evening until I saw it start to glow. The lower on fuel you get the brighter the light, if it is working. The needle was on "E" for quite a bit before it started to light up, but after twenty three years it still works.
When are we going to see you at one of our "Classic Vette" nights over at Hills n' Dales? We are having them twice monthly now. The second and last Tuesday of the month thus far. The last one was awesome weather wise, you should come out and have a cold one with fellow Vette owners. I know you have a fairly new kiddo in the family but when you feel you need a break from it all, come on out. I know, I have a 13 month old boy at the house. we are usually there from 6:00ish to 9:00ish or so. Some stay late, some blow out early but it is a hoot.
[Modified by CVT4ME, 3:01 PM 10/11/2003]
Yeah the norwegian 1980 site is excellent. Lots of time and effort has gone into his technical articles.
CVT4ME, It sounds familiar with the wipers - mine have been doing exactly the same (amongst other things). I thought you may be surpised to see this old thread come back up again, but I was searching the archives for other threads like this, and found yours. I missed it first time round, so I thought it was the least I could do to give you a hand after all the useful photos!
You'll need to do a few checks (If u can be bothered :D ) before I can help you much, but rest assured it's probably something thats come unstuck in the controller.
Have a listen to the controller when you stick it into delay. The relay should click then and only then. That relay switches over from letting a permanent current flow to the motor (i.e for 1, 2 mist) to letting the electronics of the
controller decide when to cut/provide power.
It should click when you go into delay, click off when you move up to 1, and click again as you come back down to delay. If it doesn't do that, check the condition of the green wire out of the controller (hopefully your 80 should have similar wire colors as my 80!)
To be honest, a good check of all the connections on the board would help the weight of the board on the solder, where the wires meet, can create cracks.
If the relay is doing it's thing, it could be a problem with the big transistor that has the big heat sink clipped onto it.This has started to go on mine, so my intermittent wipers kind of "judder" across the screen when they've been on for a while and heat builds up in the board.
I've not worked out a suitable replacement for the transistor yet, but i'm gonna have a chat with one of our electronics guys next week, so will let you know after that what would make a good replacement.
If you can get hold of a decent multimeter it would be half the job done - there's a lot of wire you might have to check for continuity.
Cheers!
:cheers:
(You're right about the assumptions of how it works, by the way!)
[Modified by theoUK, 7:35 PM 10/11/2003]
[Modified by theoUK, 7:37 PM 10/11/2003]
yep... i had (am having) the same probs with my intermittent. They weren't working when i bought the car, but i had the transistor replaced and got them going.... for a while anyway. Now they work for about 60 seconds then give up.
I guess i need to find a beefier transistor but i'm not really well versed in electronic components so i've gotta find someone who is. When i first had the transistor replaced, no one could recognise it by the markings on the side so we just went for something similar and hoped it would work.
If you manage to find out the right one to replace it with , please let me know........ and i'll do the same.
i could REALLY do with intermittent now that the winter is coming! .... i also wish the wiper control was on the steering column (was that 77 only??).. but thats another story!) :D
CVT4ME, it's good news that you hear the relay click - at least some of it works! When you put the switch to delay, you should be grounding the purple, black/white and dark brown wires from the controller. If you pull the plug on the controller and test for continuity to ground on these wires, then at least you can isolate problems to just the board. It sounds like it might be that big main transistor, passing current even when it's not supposed to be.
Can you remember where you saw the schematic for the board?? That woud be bloody useful! I have tried to draw the circuit by following the tracks myself, but I can't be 100% sure it's totally correct - still it has helped a bit in understanding whats going on. If you can get hold of that it would be a Good Thing. I've searched high and low, but not hard enough, obviously!
Skeets - did you replace that big transistor with the stoopid great heat sink clipped onto it? I'm guessing so, 'cos i think that's the root of the problem. My intermittent works for maybe 5 mins, then the wipers start to judder, or work full-time, or not at all. At least you've managed to choose a replacement that functions right - but looks like it doesn't have a big enough power rating.
The big trans has to take all of the motor current thru it. The current to run the motor on intermittent or slow is about 6 to 8 amps, all of which goes through that trans. So at 12 volts, i guess you need a trans that will take about 8*12 = 96 Watts. When the car's running and the alternator is pushing out 13 - 14 V, then perhaps over 100W is more like it. What rating was the one you used? (I've tried the texas instruments technical help people - its a TI trans on my board -but they weren't particularly helpful being as it's such an old thing) I guess it's gonna be down to trial and error. Hopefully a more modern replacment trans might be able to take the power better. I'm gonna speak to a guy who can hopefully help me this week, so I shall keep you posted!















