Wiper Diagnosis

Wiper works only on high and doesn't reset to home when shut off. My thought is to check switch and/or relay before jumping to wiper motor. Am I on the right track?

Which car, which system.

Looking at a wiring diagram and knowing how this system is ment to work will give you a headstart.

Motor itself when working on hi speed is not suspicious to begin with.

2002 GMC SIERRA

Oops, see below :silly:

juergen.scholl wrote:

Do you have access to a scanner that will show command/control signals (actual versus desired for example )to and from the wiper control module?

Otherwise confirm the corresponding voltages to the module: if they are correct the module itself is at fault.

Unfortunately my Thinkscan Max doesn't have that capability

Richard6767 wrote:

Unfortunately my Thinkscan Max doesn't have that capability

Then test with a multimeter directly at the wiper stalk and at the module terminals for the respective voltages depending on the wiper stalk position.

Test the switch inputs at the module just to be thorough but I doubt they'd cause loss of low speed and no park. It sounds like a low speed problem inside the wiper module/motor assembly. Not one I'd fire a module at but the cannon would be loaded :silly:

Also the switch contains resistors so you'll sometimes see less than battery voltage on Mux1 & 2 depending on what position the switch is in.

When I get home I will test this.

Thank you for this, when I get home I will try this.