My symptom, front windshield washer works, rear one does not.
Ford uses a common pump for both front and rear washers. There are 2 hoses coming out of the pump, one to the front washers, the other to the back washers.
Front washer - 12 Volt powers the pump to pump water to front washer.
Rear washer - reverse the voltage to the pump, reversing pump direction to pump water to the rear washer nozzle.
I have removed the pump from inside the fender well. When I connect 12 Volts to it, pumps water out one discharge port. When I reverse the voltage (and therefore reverse pump direction) it pumps water out the other discharge port. When I put the pump back in, I can operate both washers supplying external 12 Volts and reversing the connection.
My problem is the pump operates to the front windshield, however, does not operate the rear washer. It does not operate, there is no voltage present and no clogs in the water line. I can blow air through the line and it bubbles in the washer tank.
I have changed the pump, the turn signal switch that activates the front/rear pump and the rear wiper. Fuses are good for both front and rear wipers.
Obviously a wiring problem since I have changed every component in the system.
Where to start looking?
I got into the Ford wiring and am still frustrated.
2012 Escape, front washer works, rear washer does not.
There is only 1 pump on the washer reservoir inside the front passenger side fender.
When I operate the washer on the front, the pump operates and I can hear it while spraying water.
When I operate the washer on the rear, the pump does not operate and I cannot hear it.
Ford was innovative when they wired it.
Connect 12 VDC to the pump one way and it pumps fluid to the front, reverse the 12 VDC power at the pump, the pump runs backwards and pumps fluid to the rear washer. I proved this using a 12VDC supply connected to the washer pump.
Reverse the power connection and fluid goes the other way to the other window.
I have replaced the washer pump with no change to the symptom.
I also replaced the wiper switch on the steering column.
It appears there are relays in both the front windshield wiper motor and rear wiper motor that perform the magic of reversing the voltage at the actual washer pump.
I have now replaced both the front wiper motor and rear wiper motor twice and I still have the same problem.
Must be a wiring issue, although I cannot find the wire return from the rear wiper motor that will operates the pump in reverse to squirt water to the back washer nozzle.
Still frustrated and the back squirt nozzle does not spray water.