Several weeks ago the “check brakes” light came on in our 2000 Ford Windstar. The next day the speedometer quit working, the air conditioner would only blow hot air, and the odometer only showed dashes.
After a little research, I found that this is a very common problem with Windstars. There is a switch (called the brake pressure deactivation switch) hooked to the braking system that detects when the brake has been pushed and stops the cruise control accordingly. Well… this switch is known to develop leaks, which allows brake fluid to run down into the wiring and cause a short. This blows the fuse which controls the speedometer, A/C, odometer, etc…
With a little more research I found the parts were inexpensive and it was a relatively easy DIY fix. So, here is a documentation of “what worked for me”. Hopefully anyone else with this same problem will find this helpful. Of course, differences between different model years may vary these steps somewhat. And by the way… while I hope this post helps someone, I’m not legally responsible for anything you do to your vehicle or the consequences thereof.
Your first step is to see if your fuse is blown. The fuse box which holds the fuse is located under the dashboard on the driver’s side. The green arrows in these pictures point to it:
There is a black cover on the fuse box. Holding the bottom of the cover, pull it away from the box to remove it. Now you should see something similar to this:
Find the circled fuse (#10, according to the map on the cover), and pull it out. Hold the fuse up to light to see if it is blown or not. This is the picture of my blown fuse:
This is the picture of my new fuse:
If the fuse is blown, you will need to buy a new one. I bought mine at Wal-Mart for around $2.50. Make sure you get a fuse that matches your old one. I bought a pack of ATM 10 fuses made by Buss. Here is the package:
The next step is to verify that your brake pressure deactivation switch is truly at fault. To do this you will need to remove the air filter to get access to the switch. This is a picture looking at the front of the van with the hood up:
This short video clip shows me removing the air filter:
This is what it should look like with the air filter removed:
The arrow points to the switch we are looking for (it doesn’t look like a traditional light switch). There is a cable plugged into the bottom of this switch. On mine the cable was wet with brake fluid and grime (more than normal). This is what caused the short. If yours is wet with fluid, you likely have the same issue I did.
Next you will need to get a brake repair kit. Motorcraft makes the one I bought from my Ford dealership for $18.68. The part number is XW7Z-9F924-BA. This is what it looks like:
It consisted of a new switch, an adapter cable, and a plastic tie. You can also buy it online at https://www.tituswillfordparts.com/
Now for replacing the switch… first you need to disconnect the cable that plugs into the bottom of the switch. Squeeze the sides and pull downward and it should come off. This is a picture of me pulling it off:
Next you need to get the new switch within easy reach. This is because when you take off the old switch, brake fluid will slowly leak out. The quicker you can screw the new switch in place, the less brake fluid you will lose. My new switch had a protective orange plastic cap over the threaded end. If yours has this, take it off now. With the new switch close at hand, use a 9/16 inch open ended wrench to loosen the old switch. Here is a picture of me doing it:
Unscrew it the rest of the way by hand and quickly screw the new one back in place. You may want something under the car to catch any brake fluid which drips out. I only lost a tablespoon or two.
The repair kit should have come with a new cable. One end plugs into the new switch and the other end plugs into the old cable end. You may need to clean off the old cable a little to prevent a new short!
This is a picture of the new cable installed:
Next, you can use the plastic tie to hold back the cable in a safe place. Here is a picture of how I routed it:
My brake fluid level was down significantly from leaking, so I then added fluid to the master cylinder (the plastic tank on top of the new switch). This is a little tricky to get a funnel into, so I used a short piece of CLEAN plastic tubing to pour it in.
Now simply reinstall the air filter (don’t forget to reconnect the hose in the back!), and replace the fuse if you haven’t already.
Some sites recommend disconnecting the battery when replacing the fuse. I didn’t, but it is probably good advice.
After everything is reassembled, start the car. You should having a working air conditioner, odometer, speedometer, and no “check brake” light on your dashboard. If the brake light is still on, double check the fluid level again. Mine needed almost half a pint.
Finally here is a picture of the old part:
This procedure worked great for me and saved some money. FYI… there is an investigation ongoing which may result in Ford having to do a recall because of this issue. So save your receipts and you might get reimbursed later. For more info on the issue go to