Problem: Windshield Wipers With Mind Of Their Own!

Discussion in '2005 - 2014 S-197 Mustang -General/Talk-' started by slam_154, Dec 18, 2013.

  1. Hey guys, got a problem I've been dealing with for some time now and wondering if anyone else has experienced the same or similar. A few years back, my wipers just started going off on their own at random and I could not control them at all. Had to let it go for a while because I didnt have the money to deal with it at the time. A couple weeks later, smoke started rolling out of the cowl vents and I ended up having to pour a Mt. Dew on the wiper motor that had caught fire, not cool lol. I took the car to the dealership and they pulled the half melted wiper motor and revealed that it had somehow got stuck between high and low speed and shorted out. They replaced the wiper motor for $400 and it worked fine for about 8 months then they started going off on their own again. Before I could pull over out of traffic, the wipers stopped but then started discharging the entire wiper fluid reservoir and would'nt stop until it was empty. Finally got pulled over in a parking lot and I pulled the fuses to the wipers and the wiper fluid. Now I've just been making sure I keep a fresh coat of Rain-X on often and have dealt with the rain for the time being. So my long stories question is, Would this be a wiring issue where I would have to completely replace the wiring? A computer issue? Or was it just my luck that I got two faulty wiper motors in a row? Any input would be appreciated. Thank you!
  2. It sounds to me like the wiper control on the steering column is bad as that is the source of the commands for the wiper motors and the wiper fluid pump.

    I'm not sure exactly how the wiper motor control works, but I suppose it's possible for the wiper control to short and command low and high speed at the same time. I unfortunately can't get to my wiring diagrams for the car until this weekend so I can't look it over, but there is probably a harness running to the wiper control that you could test.

    I seriously doubt it is the wiper motor itself causing all of this.
    slam_154 likes this.
  3. Good info, I'll try to look into that. Thanks for the response. I always get the run around from the local dealership and they keep trying to tell me that its my aftermarket parts causing this (I have a CAI, full exhaust, and UD pulleys and aluminum drive I just rolled my eyes and walked out at that point). haha
  4. I just had a few minutes to look at the shop manual and the wiring diagrams. There is apparently a fair amount of circuitry in the wiper motor itself, more than I would have thought, but I would still suspect the switch. If the problem happens when you put the fuses/relays back in, you might see if the problem persists when you remove the wiper switch itself from the steering column. If the problem goes away, you can always test the switch out of the car and see if it is operating correctly. If you have a meter and can test continuity, you can check to see which wires a showing continuity to ground.

    To remove the switch:
    - Remove the 3 screws (on the bottom of the steering column) and the upper and lower shrouds.
    - Remove the 2 windshield wiper/washer switch screws
    - Disconnect the electrical connector and remove the windshield wiper/washer switch.

    For the connector, there are 12 pins, the top row is 1-6, the bottom row has pins 7-12. The top of the connector will have the clip, the bottom will be flat with no "bumps" on it. I am looking at the manual and not that actual unit, so if you have trouble, PM me.

    Pin 2 is the ground connector, with the switch completely off, pin 2 should not have continuity with ANY other pin. If it does, either the switch is not really off, or it has a problem.

    When the washer switch is depressed, pins 2 and 5 should have continuity, otherwise, they should be open.

    For the low speed wiper, you should have continuity between pins 2, 6, and 12. Pins 1 and 4 should be open (no continuity with pin 2).
    For the high speed, you should have continuity between pins 2, 4, 6, and 12. Pin 1 should be open (no continuity with pin 2)

    There is another table for the intermittent, but you didn't seem to be having an issue with that one and it is a bigger table that would be easier for someone to scan in :).

    It appears a new switch is around $130 or so from the auto parts store, and since you don't have the fuss with the air bag, it even appears to be easy to replace.
  5. Hey thanks for the help! I ended up replacing the switch and put the fuses back in. Everything seems to be working properly for now, so hopefully it stays that way.
    jay07 likes this.
  6. common problem def the multifunction switch