wipers wont shut off on Tahoe

My bud has an 04 or 05 Tahoe,not sure which,but he was telling me that he pressure washed the truck the other day and now the wipers wont shut off unless the truck is shut off.I don't know if he used the power washer to do under the hood or not I never asked him but I'm thinking he must have because everything worked fine before.I searched for wiper motor issues but didn't find anything anything that pertained to his problem but I understand that there are some related problems with the turn signal stalk with some trucks too,could the contantly running wiper motor be caused by a fault in the turn signal lever?
I will most likely be helping him to trace out the problem and would like some areas to look at so we aren't chasing our tails.

Not sure on this '04, but my '98 Sub has a circuit board in the wiper motor. Could be it got shorted out.

Guess he doesn't like his truck. I think Stickman got it. He shorted the module and now the wipers wont 'park'. But it might return to normal after it dries out completely.

To answer your question yes your multifunction switch will control the wipers on and off but I would guess he got something wet under the hood.

to power wash this vehicle's engine bay is a very bad thing to do.

wipers not working correctly is a small cheap problem. the wiper control board should be removed and dried. most likely the circuit components are damaged.

what will most likely occur next would be KS failure.

to power wash this vehicle's engine bay is a very bad thing to do.

wipers not working correctly is a small cheap problem. the wiper control board should be removed and dried. most likely the circuit components are damaged.

what will most likely occur next would be KS failure.
How would we go about getting this wiper control board out?

On my '98, 3 or 4 screws hold the cover on. Pull the elec connector off and remove the screws. The board will come off with the cover. This '04 may be different. May be a 15 min job if you have the replacement in hand.

Well I was up to see my bud last night and asked him if he washed under the hood and he said no so I guess this wiper problem just cropped up on it's own.Is this a know issue with the mid 2000 year truck?My 99 never gave me an ounce of trouble in the wiper system.We are going to try and get the board out this weekend and see if it can be fixed,hopefully something simple like a burned circuit board trace.

Well I was up to see my bud last night and asked him if he washed under the hood and he said no so I guess this wiper problem just cropped up on it's own.Is this a know issue with the mid 2000 year truck?My 99 never gave me an ounce of trouble in the wiper system.We are going to try and get the board out this weekend and see if it can be fixed,hopefully something simple like a burned circuit board trace.

the wiper motor has a plastic cover , that cover removed is the electrical control circuit. costs about $60.oo.