Rear wiper motor

dodge
caravan
engines

#1

2001 Dodge Caravan in which the rear wiper motor has failed. With the dash mounted rocker switch in the neutral position (Neither intermittent or a continuous wipe) I have three wires back at the motor. One would be the ground, one intermittent and I presume the other continuous. When the ignition switch is in the on position I have one wire that is hot and is not affected by what position the rocker switch is in. Any input?


#2

The wiper switch is in no way connected to the wiper motor. The wiper switch tells the Body Control Module whether you want no rear, intermittent, or continuous. The BCM then operates the rear wiper accordingly.

The three wires at your motor are:
fused power, hot whenever accesories are energized
ground, constant
signal from BCM to wiper motor.


#3

So from your reply, it appears having one continuous hot wire is correct. The fused power would evidently turn on with the key in the on position.


#4

I’m not sure how your’e going to diagnose this without a scan tool, since you’ll need to know if the body controller is getting input from the switch and then in turn is signaling the wiper motor on.
At the rear wiper:
gray/pink–hot any time key is on
black/light green–ground
brown/light green–signal from BCM

If you have a good fast voltmeter, I guess you could probe the signal wire and look for some change when you turn the switch on. If something changes, you have a faulty motor assy or a bad ground. Do your testing with the hatch closed. I’d also check the wiring harness where it flexes at or near the hinge. If I remember, BCM will not allow wiper operation if it thinks the hatch is open.


#5

‘asemaster’ is correct. The fused, hot power is there to return the wipers to the ‘parked’ position. The wipers require power to the signal wire to run. The BCM will send a constant power through this wire for continuous operation, and a pulsed signal for intermittent operation. The fused, hot wire makes sure the wiper returns to ‘park’ whenever the power on the signal wire is off.