HELLO GUY'S I'M NEW TO THIS FORUM SO PLEASE BEAR WITH ME I have a 2000 F-150 HARLEY DAVIDSON EDITION made in Canada my problem is the wipers won't turn on or off when the headlights are on. If I turn my headlights off then turn my wipers on they work fine even after I turn my headlights on. But if I want to turn them off I have to turn off my headlights first and visa versa. I'm a little stumped never seen this before on any vehicle. Any answers

 

I have been noodling on this for a few days, and cannot think of an obvious reason why it is happening.

This leaves you with starting from testing the MFS and working your way back into the truck, depending on what the test results are.





Sorry I don't have a better answer for you, but this one is going to require starting at step #1 to figure out.