UPDATE 8/7/2021: I'm no longer stumped, I solved the problem! See post #26 below for the solution.
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Hello everyone, I'm really stumped on this one and would appreciate your thoughts. I just bought an SRT6 roadster a few weeks ago and this forum has been invaluable in addressing a number of issues. This particular wiper issue was present when I bought the car.
I've read the other threads related to wiper malfunctions, and while some issues were similar to mine, I did not see a verified resolution.
My wipers come on with the key in the "on" position, regardless of the setting of the multifunction switch. They cycle about 7 or 8 times before stopping in random positions. This repeats whenever the multifunction switch is rotated to any position, including back to "off".
Following the procedure in the service manual, resolution is to replace the BCM. However... I am finding this difficult to believe since I have already replaced the BCM for at least one other issue. The wiper issue remained
exactly the same before and after replacement with the "new" (used on eBay) BCM.
Not being satisfied with the answer, I did more troubleshooting steps. Summary:
- I unplugged the wiper motor, and plugged in a "new" (used on eBay) wiper motor. Same behavior.
- With no wiper motor plugged in, I measured the voltage at pin 1 of the BCM. Voltage was ~12V for roughly the same amount of the time it took for the 7-8 cycles, then went to zero, consistent with the behavior of the wipers when plugged in.
- I measured the voltage at socket 65 of the wiring harness (not plugged in to the BCM). Verified proper operation of the multifunction switch (voltage at zero when multifunction switch is turned off, and ~+12V at any of the other positions (Int, Low, High).
- I replaced the wiring harness to the BCM, but removed the embedded C3 connector (so no voltage from the multifunction switch would be present at pin 65 of the BCM). The wipers still behaved in the same way (voltage present on pin 1 for a short time before returning to zero).
Thanks in advance for any help you may be able to provide.