cruise control not working

[usstitanic]

2000 Windstar v6 cruise control is not working. Owner's menu lists fuse number 10 to check but the fuse is o.k. Any suggestion where should I start to check?

[usstitanic]

Sorry, it is 3.8 V6.

[wiswind]

A VERY common cause of the cruise control not working is a leaking brake pressure switch.
This part is located on the bottom of the brake master cylinder.
FORD has issued a recall for this part......
The leakage causes a problem with the contacts inside the switch (can actually catch fire) and indicates a closed condition (which indicates that the brakes are being applied) with will disable the cruise control.

[usstitanic]

Thanks for the quick reply. You are right on the money, just received a letter from Ford about the defect today. Will take it to the dealer for repair.

[Ron AKA]

Not sure on a Windstar if it is the same, but on another vehicle I had the brake fluid level go low. The low fluid level switch disables the cruise control. I also had one where the parking brake switch was not adjusted properly, and was disabling cruise control.

[usstitanic]

Thanks for the input. The brake fluid was low and I refilled it to the max. Did a test run on the highway and the cruise control was not engaged. Will take it to the dealer.

[wiswind]

If you have not taken it to the dealer yet.....I would recommend that you unplug the electrical connection to the brake pressure switch on the bottom of the master cylinder.

A leaking brake pressure switch can cause the vehicle to catch on fire....even when it is turned off....and parked.
Unplugging the switch will prevent this from happening.

[usstitanic]

Just got back from the dealer. Did a test run on the cruise control, it is still not engaging. What else could be wrong???????

Here is what was written on the invoice:
Concern 40 09S09 speed control system modification
Cause 09S09 speed control system modification
Correction INSTALL UNIVERSAL JUMPER HARNESS
Part Number PO # Note Description
FMC 8W7Z 14A411C Wire ASY
Parts: Count 1.00 Allowance: $2.98

Fail code: A99 Cond Code: 82
Fail code: A99

Parts: $10.42
Mechanical laber $19.05
Total Charge for Concern $29.47

[wiswind]

That sounds strange......the brake pressure switch and harness should be covered under the Recall.......

They charged you for it.....and never checked on your original complaint?

One thing, other than the brake pressure switch.......if enough brake fluid leaked out....and it dripped down onto the Cruise control servo......it could have burned that out.

Another cause......did they check the fuse for the brake pressure switch (I think it is fuse #10)?
I would check the fuse FIRST......as it is about the cheapest thing.

Another possible cause would be one of the switches in the steering wheel.
ON/OFF, Set......

If it was the BOO (Brake On, OFF) switch.....then you would not be able to shift out of PARK with the motor running.
Is is not uncommon for one of the wires to the BOO switch to break off.
You then have to shift into Neutral, then start the car.....
HOWEVER, you will have NO BRAKE LIGHTS on the back of your vehicle.

[usstitanic]

They charge Ford for the $29.47. I call them about the cruise control problem and they relied that they already fulfilled the recall order. The cruise control would be a separate issue. What puzzles me is only 1 part was replaced. Is this harness including the switch? I may have to go the another dealer to find out. When I receive a servey from Ford I will give this dealer a poor rating. I checked the #10 fuse and it was good.

[wiswind]

When I read my recall information.....it looks like they only replace the switch if it is leaking, but replace the harness on all vehicles.

I would check that fuse first...(I know.....you checked it...but give it another look...post repair)...as that would be the easiest.
Also look at the switch...and see if there is dampness on it.

If the switch is damp with brake fluid....then it would be sending a constant signal that you have the brake applied.......which would prevent the cruise control from working.

After that.....it gets down to troubleshooting....checking for voltages, switches, ett.

[usstitanic]

Will check the fuse again. I will look into the repair this weekend in the day light hours. Been working long hours and loosing day light during the week days. Will report back later and might ask for troubleshooting tips here.

[usstitanic]

The dealer did not replace the pressure switch that was attached to the brake master cylinder. It still has brake fluid around it. They replaced the old wiring harness with a new one that has a fuse in between. That is all they have done to the recall. I unplugged both ends of the harness and cleaned up the fluid. Measured the resistance of the pressure switch which read 47k ohms. I also measured the other end which read 1M ohms. I shoud have measure the voltage to the switch which I did not. Will do that next time.
For troubleshooting, I will unplug the harness from the pressure switch and short out the 2 wires to see if the cruise control is back or not. Any suggestions from the group?
Will report back again.

[wiswind]

If the switch is wet with brake fluid, I would buy and replace the switch.....it is a cheap part....and very easy to replace.....so not worth fighting with the dealership over.
The switch being wet with brake fluid would move it to the top of suspected causes of no cruise control.
I wonder if the dealership was out of them?

[usstitanic]

I bought the switch from the same dealer and they have plenty in stock. I measured the 2 terminals of the switch and it read zero ohms. Will report back after the installation.