I own a 1996 Pontiac Transport. The windshield wipers will only work on high speed. The motor has been replaced and since they have a plastic body I figured that mabye this was a ground problem. I grounded the wiper motor with a separate cable however this did not fix the problem. I have since replaced the wiper switch but this made no difference. The wipers will work for short periods of time usually if the speed is above 110 KPH on the highway. This van has one of the most unusual arrangements for the wipers that I have ever seen usuing what GM calls a wiper transmission. The van has 130000 KMS on the odometer. Are there any things that I am overlooking. I know that the electrical board is part of the wiper motor and is it possible that the problem is with the board itself and not the motor at all. Any ideas would be greatly appreciated.
I had intermittent problems with what ended up being a bad plug to the wiper motor. Broken wire.
I went to a salvage yard, cut the plug off another similar wiper motor, and spliced it into mine, and had no more problems. I had tried cleaning the contact board, and even another wiper motor with no cure.
On my 97 transport, they had problems with the wipers parking. Typically they won't park, or will stay fully up, when you shut them off. While you may think it is the wiper motor, it's not. Instead what it turned out to be, was 2 things. Corrosion of the return assembly that sits above the wiper motor.
You have to take that peice out, and soak it and then apply thick oil or grease to it. However the real problem was cured using a tiny set of jewlers needle nose pliers. It turns out there is a tiny lever that is what makes them park that has a tiny brass spring that pushes it out to engage with a tooth, so that when the wiper motor reverses to park the wipers. Well it got weak and the lever would fail to engage the tooth and move the cam causing the parking action. A simple bending of the brass spring to cause the lever to have better action, cured the whole problem. You will have to play around however when you put the cam back onto the wiper motor to find the right position to make it work. And if you get it off by any amount it causes the wipers to over shoot and either fail to park or else they bounce back up on each wiping. Be careful playing with it, as you could easily injure yourself. Once you find the right position is where they park consistently and do not overshoot and bounce up on each wiping acition. They get annoying if they bounce up and also block your view of the road if adjusted wrong.