When I bought my car I had a bad case of the phantom wipes, when I started the car, when I hit bumps, when I used the turn signals. I got the Rodney Dickman kit for the wiper board, and that took care of the wipe when I started the car, but that was it. I then got the turn signal stalk, only because that sounded like an easy possible fix, but of course that did nothing. I finally broke down a bought a brand new switch (the '88 version because I've heard they're better) and it looked like my 'phantom wipe' was a thing of the past. Here I am less than a year later, and now I'm getting a wipe when I hit my signals again!
Any ideas how this could possibly be?
Edit: The car is an '85 GT with tilt and no cruise.
[This message has been edited by NetCam (edited 06-29-2013).]
Do you use the wipers a lot, I have found that on a lot of older GM's that don't get driven in the rain something funky happens in the switch. and they seem to get MUCH better with use. With the Ignition off just work the wiper switch through the motions for a minuet or two. Off, On, Off, On, High, Low, High, Low & move it through the delay portion. It will either be much better or much worse, either way you would know it's the switch. but I guess if there was no change you haven't lost but a Min. or to of your life.
I would suspect the power diodes on the control board. I had this problem, and traced it down to these diodes. I found replacements at Radio Shack, but I can't find that info now. And... I had to mix & match them. As I recall, there are two on the control board. I tried a random two diodes from the pack of four I bought. Still had the phantom wipe. I did a little circuit analysis, and found that these diodes need to have a very low reverse leakage current. Fortunately, at the time I had access to some equipment at work that could measure the diodes. Two of them had low reverse leakage current, two did not. I put the two good ones in, and it's been working find ever since. I'll look to see if I can find my info on that repair.
Sat in the car on the weekend while at a cruise night waiting to pull out and played with the control for a couple of minutes. So far I haven't had a return of the phantom wipe, so maybe every now and then I should repeat the process to keep the switch 'fresh'.
Does you car have tilt? Without going into the control board, anything that can make ground contact can cause a phantom wipe. Inside the wiper motor is a set of contacts like a relay. It only takes a momentary short to move the motor to where they close. Once they close, the motor will complete a cycle unless you kill key power. Lets say you have a set of wires connected to the battery. One pos. to the motor, one neg. to the motor(always connected through the contacts) and one in your hand(connected to the motor directly). Just touch(not held) the one in your hand to the neg. post on the battery or any grounded metal and the motor makes a cycle. Crud in the switch or a bare wire, both will cause this. Sloppy tilt will cause fine small metal particles to collect in the collum and collect in the switches. If the tilt is used a lot or if it is sloppy the wires inside the collum can get worn also.
The car does have tilt, which i use all the time. I find it way too tight getting in without tilting the wheel up, and feel lime I'm driving a teeny tiny bus if i don't pull it back down. Maybe over the winter I'll take the shroud back off from under the steering column and give all the wires a good look. I guess the other option would be to put in a cutoff switch on the power to the wipers, but i was hoping it wouldn't come to that or I wouldn't have dumped about $70 and two hours work into replacing the switch
Ive had this problem with other cars. What ive found is that when not using the switch for long peroids of time leads to corrosion almost like carbon tracking in a distributor cap, but on the switch itsself. this can cause elect to conduct across that path. Using the wipers more often will solve that problem like they said but the fix is to use electrical wash , clean the switch and reapply dielectric grease to the contacts. Electricity can do some really odd things. weirdest thing ive seen is all Vac lines on a 95 Blazer glowing . shorted out plugwires somehow reacted to something in those Vac lines and caused a glow up them when that wire fired. You all prob know what Vac lines im talking about, the ones that turn to Black dust/powder after a few years .