[3rd Gen : 96-00]: Crazy rear wiper
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Crazy rear wiper
When I first start the Caravan, the rear wiper will spontaneously run. It may do one cycle or many. It eventually shuts off on its own.
when this occurs the wiper switch seems to have no effect on shutting off. But the wiper switch does turn it on. I want to say it does this more when cold, but this may not be true.
This is a 1998 Grand Caravan ES with 3.8L, rust free CA van
Any ideas?
when this occurs the wiper switch seems to have no effect on shutting off. But the wiper switch does turn it on. I want to say it does this more when cold, but this may not be true.
This is a 1998 Grand Caravan ES with 3.8L, rust free CA van
Any ideas?
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The front wiper has never spontaneously started like the back one.
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Actually, its not when I start the Caravan, all I need do is turn the ignition to RUN, engine off. About 90% of the time, the rear wiper will run once, then stop. The remainder it can run for several cycles. Battery is fully charged. Fuses are fine.
I read somewhere that someone had something similar and traced it to the wires in the door jamb on the drivers door. Seems unlikely, but I checked and don't see anything odd. I pressed on the wires and nothing worsened or improved
Maybe it is just a corroded switch. Anyone know how to remove the panel holding the switch?
I read somewhere that someone had something similar and traced it to the wires in the door jamb on the drivers door. Seems unlikely, but I checked and don't see anything odd. I pressed on the wires and nothing worsened or improved
Maybe it is just a corroded switch. Anyone know how to remove the panel holding the switch?
Last edited by 98GrandCaravan; Jul 29, 2021 at 03:38 PM.
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I took the wiper/HVAC control assembly apart. The "switches" for the rear wiper are rubber keypads just like found in a TV remote.
I have cleaned the pads and the PCB, and have examined the PCB under a microscope. I don't see any defects.
When I reconnect it, and press buttons, the associated LED lights indicating the keypad is working. However, the rear wiper reacts strangely.
Now the washer seems to run, though intermittently, when any rear wiper operation is selected. When continuous wiper is selected, it runs a few times and then stops. The wiper/HVAC control assembly apparently communicates with the BCM under the dash. It is the BCM that drives the wiper.
Given that the wiper behavior has now changed after messing the with controls, I'm inclined to believe the trouble lies in the controls and not the BCM
[UPDATE]: I have ordered a latest version wiper/HVAC control assembly; 4677617AE, off ebay. We shall see if it is this assembly or the BCM
I have cleaned the pads and the PCB, and have examined the PCB under a microscope. I don't see any defects.
When I reconnect it, and press buttons, the associated LED lights indicating the keypad is working. However, the rear wiper reacts strangely.
Now the washer seems to run, though intermittently, when any rear wiper operation is selected. When continuous wiper is selected, it runs a few times and then stops. The wiper/HVAC control assembly apparently communicates with the BCM under the dash. It is the BCM that drives the wiper.
Given that the wiper behavior has now changed after messing the with controls, I'm inclined to believe the trouble lies in the controls and not the BCM
[UPDATE]: I have ordered a latest version wiper/HVAC control assembly; 4677617AE, off ebay. We shall see if it is this assembly or the BCM
Last edited by 98GrandCaravan; Aug 30, 2021 at 06:56 PM.
