Hi, I drive a 2004 dodge Intrepid with a 2.7 in it. I have a problem with my windshield wipers. When I turn them on low they sometimes go at the rate they should, but often they move much faster than they should. When I turn them off sometimes they stop at the bottom of the windshield like they should, but most of the time they stop in the middle of the windshield. I can live with this but I'd like to get it fixed. Does any one have any idea why it does this, and if so Do you know how to fix it.
Now here's where I chime in to a thread of my "area of expertise".
have you tried sending the switch from "off" to "hi" and back very quickly many times? and do the wipers park mid swipe in delay, or for instance turning off the car while they are in mid swipe, and leaving the switch on, which will trigger several swipes upon ignition power up to "re-calibrate" the park switch with the BCM (I think its the BCM, but don't quote me on it) So try the on off a few times and report back.
When I turn on the wipers to high and then off quickly it doesn't seem to do anything unexpected. They speed up and slow down. When I turn the car off in mid swipe sometimes they stay on and go to the bottom of the windshield and then stop, and other times they stop in the middle but when the car is turned back on they move to the bottom and with no calibration swipes.
Its an issue with the park circuit in the motor....mine does it here and there, Ive owned the car 7 years and it has done it the whole time....just occasionally. I click the switch once and they return to normal, or park where they need to. Wipers always work, so I never dealt with it.
For it to stop in the middle of a sweep instead of going to the park position to me says something is not right with the signal circuit to the BCM, not in the motor park switch. By that I mean that anything in the middle of the sweep to give a false park position indication can't be a very strong similarity to contact closure - meaning it would likely be a high resistance, not low resistance like a true contact closure would give. The circuitry that reads the signal should be designed better to reject anything other than a very low resistance contact closure. If I were to try to fix this, I would attack the electronics end and/or the way the wiring is done. There is a huge ground loop the way that switch is grounded - all the way up at the headlight ground point (*and* the wiper motor ground is on that same wire - the wiper motor is a *huge* noise generator on that ground wire), whereas the signal is *read* relative to the BCM ground.
For it to stop in the middle of a sweep as if it were at the park position says to me that the electronics has very poor noise immunity, either from lack of "stiffness" or detection thresholds, or due to ground loop - all of which make for poor noise immunity. I'll bet if you cut that ground wire and ran it directly to BCM ground and buffered it with a well-designed schmitt trigger and possibly some light low-pass filtering, maybe even an optisolator (designed properly) - all in the harness between the motor and the BCM, that it would work flawlessly. It may only take cutting the switch from the motor ground and running it's own ground wire to the BCM - not sure how easily the switch ground could be to cut/separate from the motor ground, and there would have to be a way figured out to run an additonal wire out of the wiper motor. If that didn't do it, then additional buffering circuitry *would* be needed between the wiper motor and the BCM.
I don't see it as a problem in the contact itself *IF* it stops in the middle of a sweep. If it goes past the park position when turned off, that's a different story and could be explained by the contacts being dirty (high resistance in the contacts of the park switch). So yeah - it could be either or both on a given car depending on the exact behavior.
'98 LXi - Later Concorde gages (black w/ chrome rings)/'99 LX - LHS gages (white) - HIR bulbs