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Mercury moutaineer

sometimes the wipers will not work on my vehicle. The dealer can find nothing wrong. What gives?

Could be the control switch or the wiring on the steering column.

Thanks. But the dealer said he removed the control stalk and tested it - working fine. He also said their diagnostic tests indicated all wiring was functioing normally. This is really frustrating. Other than this issue, it’s a great vehicle, albeit a thirsty vehicle.

Do you tilt the wheel up/down as you enter/exit the truck ?
It has been known to happen, that a liitle tab inside the gang plug behind the multi switch breaks allowing the wire to come loose on occasion. A ‘tilter’ will experience this more often but a non-tilter can still get the intermittent dis-connect.
With the column trim off, wiggle and pull each wire in the gang plug, none should come out. If one does come out, a new gang plug is needed. Pushing it all the way back in will give you a live circuit in the mean time.

Have the dealer check the ground path from the motor to the body. The wiper motor is usually isolated from the body by rubber mounts. There has to be path to ground the motor/gear box for the current to flow. The wiper linkage is not sufficient for grounding purposes.

When the motor is not working, measure the voltage drop between the motor/gear box and a good ground spot on the body. If you see more than 1 volt DC, fix the ground path.

Hope that helps.

Thanks for the suggestion. I will do just that.