Windshield washer problems

I believe on them Prostars the circuit goes through the BCM (Body Control Module) which is similar to the ECM but used for accessory functions. When you press the wiper fluid the BCM turns the wipers on intermittently.

Brakes popped, key on, try pushing the cruise "ON" and "Resume" at the same time and see if any trouble codes are displayed on the VID if your truck has that option.

Another possibility is a wiring/connector issue.

 

There is no relay. The washer pump is not computer controlled, but the computer does monitor the same wire. The washer pump is supplied ignition voltage and is grounded directly through the washer switch at the end of washer/wiper turn lever. The body controller is also connected to this same wire and is watching for the ground signal when the button is pressed so it knows to run the wipers. You must have an open wire some where. If you press the button in, do the wipers come on at all? If the wipers do come on, the broken wire is likely outside, but if nothing happens the wire problem might be inside.

 

Were you able to locate the problem as I seem to be in the same boat. I have ignition power going to the washer pump and wipers come on when washer switch is pressed but the ground isn't being completed to make the pump come on.

 

Having the same issue.
2007 Freightliner Columbia, MBE 4000.
Have hot at the pump, jumping the pump with a prob works but can't get a ground from the switch to the pump.