Wacky wipers

[Aussieford]

Hi guys and girls,
My windshield wipers have been playing up lately. Every time I start my 2000 expy, the wipers will turn on at full speed. The only way i can get them to turn off is by playing with the switch for a minute, or, turning the car on and off. Once the wipers are off, the switch works perfectly with me being able to adjust the speed as normal. Its just when i start the car that they come on and dont want to turn off. I thought it might be the multi function switch, but since it works after the initial problem at start up im not so sure.
Has anyone else had this issue? Any suggestions of a possible remedy would be greatly appreciated.
P.S its not me just bumping the switch when i get in (unfortunately)

 

[masterhacker]

My Taurus used to do that, but only when the battery was really close to being dead

 

[Thermo]

Aussie, have you noticed that it seems to do it more often when the truck has been sitting out in the rain or you have recently washed the truck? If so, you have a leaky windshield. WHat is happening is your windshield is leaking and the water is running down the A-pillar, into the dash and then filling your GEM module with water. In your case, it is causing the wipers to do funny things. You may also be able to feel the carpet at the driver's feet being wet.

After that, you are possibly looking at a GEM module that is starting to go bad. The other thing that I would tell you to atleast look at replacing is the wiper relay. It is possible that the GEM module is sending the relay a quick pulse when you are starting the truck, which is causing the relay to pick up and stick in the ON position. By cycling the switch, you are managing to free the relay, which then causes the wipers to return to normal.

 

[Aussieford]

Thanks guys for your replies. I took it to an auto electrician and he replaced the multi function switch, and that did the trick. Thankfully I didn't have to change the module.