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Chrysler minivan wiper problems

Fix Chrysler minivan wiper problems

Chrysler Minivans have more than their share of wiper problems, ranging from wipers that won’t shut off to intermittent wipers that quit working. If you have Chrysler minivan wiper problems, all you need to diagnose the problem is a digital multimeter.

Chrysler minivans use two different systems, depending on the model year. For 1996 & 1997 models, start your diagnostics by turning on the ignition key and put the wiper switch in any position EXCEPT high. Then ground the red/white wire at the body control module (on junction block behind left side of dash). The wipers should now run at the “low” speed. Grounding the red/white wire trips the wiper ON relay located in the power distribution center (PDC). If they don’t operate at low speed, it’s time to check the fuses and wiring. If they do operate, then you’ve eliminated the wiper on relay and the wiper motor as a possible cause.

Next, check the intermittent portion of the system. On these models, the body control module (BCM) sends a voltage up to the multifunction switch (MFS) on the dark green/red wire. The voltage travels through a series of resistors and the BCM senses the new voltages on the black/white wire. To test the continuity of those wires and the resistance values, set your meter on ohms and rotate the wiper delay through the range. Delay #1 should read 1905-1915 ohms, 2= 995-1005, 3= 612-622, 4= 387-391, 5=254-258, and 6= 155-157. If you’re getting close to those readings, don’t run off and buy a new MFS because you’ll still have the problem after the replacement. Shops are reporting that as the BCM ages, it sends out a lower voltage on the dark green/red wire and the resistors then reduce the voltage to the point where the BCM can’t see it. You can either replace the BCM with a new one ($$$$), or add a 9v transistor battery in series on the dark green/red wire. It won’t draw any current when the wiper switch is off and only minimal current when the wipers are on. Of course, you’ll have to replace the battery when it wears out. The symptom here is that the intermittent wipers work a bit and then the delay portion stops working.

However, if the delay doesn’t work at all and you’ve done all of the above diagnostics, check out the park switch. This is also a common problem with these minivans. The park switch is located inside the wiper motor and the BCM uses that switch to sense when the wipers are at their lowest point on the windshield. The BCM sends voltage to the park switch on the dark green/white wire and when the switch closes, the voltage should drop to zero. So attach your volt meter to the dark green/white wire and a ground and watch the voltage while the wipers are in intermittent mode. If you don’t see a drop to zero, replace the wiper motor.

Starting in 1998-2000 Chrysler changed the system just a bit. Now, instead of supplying voltage to the MFS from the BCM for intermittent operation, it gets power from the PDC.

Finally, these minivans suffer from another type of problem—wipers won’t shut off. This is almost always caused by either a bad MFS or a corroded PDC. In fact, I’d put my money on a corroded PDC, especially if the wipers shut off sometimes and not others. That’s a sign of corrosion.

wiper relay, power distribution layout, relay layout

 

© 2012 Rick Muscoplat

Posted on by Rick Muscoplat


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