I have tried everything suggested and I am still coming up empty. I changed the multi-function switch months ago, wipers still only worked on high, no low or intermittent. Last month even high would no longer function.
Put in new wiper motor last night, no change. Changed the wiring harness from the multi-function switch to the plug under the dash today, no change.
To describe the power I have going to the motor, looking from the plug side towards the wiper motor, the left most wire is a white one and lights up my test light when the switch is on high. BUT, it will not run the motor. The next one is blue with red stripe and is supposed to run the low speed. There is no power coming in on that wire.
On both of these terminals on the motor, when I supply 12 volts directly from the battery to either of the terminals, they operate the motor.
The middle wire on the plug is ground. The next wire to the right is hot whenever the ignition switch is on. The last wire has no power going through no matter what position the wiper switch is in.
I have spliced wires near the wiper motor; the only wire coming in from the firewall to the plug that will run the wiper motor is the green one. The white one will light up the test light, but will not power the wiper motor.
I have come to the conclusion that I can either pay the stealer BIG $$$$ to try to fix this issue, or I can splice in a toggle switch like I did for my F150. I will probably go the toggle switch route.
If anyone has any other ideas, I am open to suggestions.
Have a great day