Join Date: Jul 2011
06 Mustang Fixed Leaks and Electrical (wipers)
Alright, this is going to be a long post. I have an 06 Mustang GT Premium, Race Red, 5-Speed. I purchased it used from a guy that only put 20,000 miles on it in 4 1/2 years. He always garaged it so the paint and interior look new. Now, the issue and the long road to fix it.
Although this post is primarily about the wiper issue I fixed, what I found when I disassembled the cowl cover solved my water leaking issue, so if you have a leaky Mustang, you should read.
Like many mustangs, we noticed if it was sitting in the driveway nose slightly lower than rear, water could enter the cabin and go to the passenger side floor. Then, a month ago, whenever I made a right turn the windshield washers would turn on for 1 cycle (they would go up and back down at the same speed as if I was washing the windshield). After doing all the various maneuvers I could think of, such as u-turn right, u-turn left, turn right fast to the lock, turn right slow, etc., etc., to see if I could reliably reproduce the errant wiper function, I realized I could not. The wiper seemed to be triggered by acceleration and turns to the right at speed so you feel a g-force. Nothing else would get it to trigger the wipers. OK, fine, I took it into the dealer and asked them to fix it.
Now things get interesting. The dealer cannot get it to trigger the wipers. I told them how to drive it, and they were able to see it. So they put in a new wiper switch (it's a box in the steering column that the the wiper control sticks into). They said "it's fixed, does not do it anymore" - right - I go to get it. Leaving the dealership the wipers do their misdeed. I had had it.
I went home, read the service manual, and right there under the various wiper errors is the "wipers go on and stay on by themselves" (close enough for me, since they are turning on by themselves). I noticed that the wiper switch was one fix, and the other fix was the wiper motor and/or electrical problem.
So I dug in. If you have the 06 service manual, this procedure is found in Volume 1, Section 501-16-18 - Wiper and Washer System. For those with water leaks, this section also tells you how to get the cowl cover off. However, as usual, they do not tell you everything you need to know, so I filled in the details.
1. First, put the hood up and take the wiper arms off - NOTE: I used a small gear puller, made it quick and easy. If yours are like mine, they are almost impossible to pull off, and I would not recommend prying them. Rather than pull hard and break something, use the puller. Also, I used a little 2-armed puller, you can use one with 3 arms, but it has to be small or you cannot get the arm down to hook under the wiper arm - it's kind of tight.
2. Remove the 4 little Philips screws that are in the cowl top-vent screen pin-type retainers (this is easy, there are 4 of these plastic retainers evenly spaced across the plastic cowl) then remove the plastic retainers. (The Philip screws hold the plastic retainers in).
3. Now pull out the passenger-side cowl first. There are two halves, and the passenger side overlaps the drivers side cowl plastic, so the passenger side must be taken off first. Now, what they do not tell you is that you need to take your time, the cowl is held on by plastics clips that go into firewall just below the windshield. In fact, if you look at the base of the windshield you will see the rubber portion of the cowl that sits on the glass, the clips are only an inch or so below the rubber.
Take care when you have the cowl almost out, because the "outside" corners on each cowl piece like to get hung-up in the hood hinge. Basically, this is easy.
4. Finally, remove the wiper motor. This is easy, 3 8mm hex bolts and it comes out so you can disconnect the power to the wiper motor. In my Mustang I saw lots of standing water, and pine needles and crap, and the wiper motor electrical connector was under water!!
At this point, I disconnected the electrical connector to the wiper motor and lo and behold, water came pouring out and the contacts were green from corrosion. I knew I had found the problem. The right turn or acceleration was just sloshing the water that was in the connector in such a manner that it shorted a connection.
5. I sprayed wire-dryer into each end of the electrical connector and then cleaned them up thoroughly and used a tiny emery board to cleanup the contacts. Then I cleaned out the crap and water that was sitting in the cowl. I discovered that there are two drains, one on each side of the cowl, that (when working), take water from inside the cowl to the engine compartment to dump on the road. These drains were both clogged with debris in my case. Reach down and remove each rubber drain "grommet" - (it is an open grommet with an extended rubber discharge port). These pull right out - clean then replace. You will notice they are shaped like a "one-way-valve" in that the end of the drain is shaped into a "flat pinch" so water cannot get up into the cowl from the engine compartment - however, this is what makes the drains clog so easily. You can see the bottom of the drains when looking at the firewall from under the hood, furthermore, you can remove and clean them anytime without going into the cowl. Just pull them out, clean, and replace.
6. After I cleaned the cowl area, wiper motor, cowl cover and anything else I could while it was open, I put some dielectric grease into the electrical connector for the wiper motor, reinstalled it, put the cowl covers on with the plastic retainers and Philips screws. I put the wipers back on and the wiper bolts, etc. Be careful to index them right so they sit correctly!!
Wipers work perfectly, no more phantom wiper events. Also, have not seen a drop of water even after rains or car washing.
Hope someone finds this useful,