Last friday I bought my sisters 99 v6 Cougar which she had been driving for the past 6 months. I drove it a little over the weekend and noticed something odd that Id never seen before on any of the 5 cars Id previously owned. Id be driving and when Id need to brake, Id often get the windshield wipers coming on by themselves for a few seconds. It doesnt seem to happen a lot, but enough to annoy me. Either she neglected to tell me about that problem, or its something new going on with it.
The car is still in great shape and only has 80k miles on it, so Im not dealing with a POS car here.
Does anyone know what would cause the wipers to automatically turn on like that?


Edited by: wolfbiker99

 

Weird. Does the car have a rear wiper? And if so, does it work and are all the wipers on the signal arm? And does the rear defroster work? They may sound like strange ?''s but I had a similar situation once. Let me know. You could unplug the brake light switch and let me know what happens with that, too.

 

Yeah it has a rear wiper and it does work, but I dont know about the rear defroster yet. Im assuming it does work though. But the rear wiper is on the same arm as the front wipers. You have to push it in to turn the rear one on.
Where is the brake light switch located? Wouldnt unplugging it make the brake lights not work?

 

You did say it only occurs when you depress the brake pedal, right?

 

Yeah thats right. Only when I press the brake pedal.

 

Well there has to be a short circuit or bad ground. Unpluggging the brake light switch(under dash/rear of brake arm)should surely stop it. But curing it is a different story. I asked about the rear wiper/defroster because I had a car that I was working on a couple yrs. ago. Whenever the lady hit the brakes, the wipers(rear one, too) would come on as did the rear defroster. After a afternoon of trying to figure this out, I discovered the rear defroster was unplugged on the hatch. The plug also powered the rear wiper. So when she hit the brakes everything went whacko because the third brake light on the rear window became ungrounded because the switch was unplugged. In short, that plug was part of a larger circuit loop, which became a open loop when it was unplugged. Do you have a multimeter, test light, etc. on hand?

 

I dont where I am at the moment. I have one in my tool box but its at my folks place. I can pick that up either tomorrow afternoon or this weekend.
Where would you suggest I start checking with a multimeter?

 

If the rear wiper is in the on position when you hit the brakes, does it move w/the fronts? Did you unplug/remove the brake light switch? I think the switch went bad and is shorting out causing this strange reaction.

 

The rear one hasnt moved when the front ones have.
Like I said, it doesnt happen every time I hit the brakes, but only sometimes. I drove last night for about 45 minutes and it only happened once, but a few days ago I drove for 15 minutes and it did it 4 times. Its pretty random.
I havent removed the switch yet, but if it were the switch, where can I get a replacement one?

Edited by: wolfbiker99

 

At your local parts store. If you want genuine Ford parts then you must go to the dealership and pay an arm and a leg. That''s up to you if you want to spend the $$$$, but I would go to NAPA, etc. Did you unplug it yet? Might as well and see what happens. It''s not like you have to risk getting a ticket for no brake lights. Just sit in your driveway and keep depressing the brake pedal and see what transpires. I''m guessing the wipers are not going to move. Let me know.