I bought a 2000 Ford Windstar and the cruise control doesn't work.


I was hoping it was the Cruise Control Cutout Switch (Motorcraft SW-6351) and since it was so cheap, I replace it. That didn't help.


The brake lights turn off when I let off the brake, so I'm assuming that's not the issue.


I checked all the brake/ABS/cruise control fuses and they were all fine.


What should I do next to either diagnose the issue or use swapnostics on other cheap parts?

 

I tried this check but couldn't get a speed control light to illuminate. I don't know if a 2000 has a light. Maybe this applies to only 1st gen windstars.

http://www.fordforumsonline.com/threads/self-test-cruise-control-check-engine.1486/

 

I'll have to try the horn to make sure the clock spring works

 

I found how to rest the servo...
Access the speed control servo located in the right hand side of the engine compartment. Perform the following circuit tests by backprobing the 10 pin connector 122 of the servo.

a. Pin 7, Red and Black wire, this pin should have battery voltage from fuse 10 in the under dash fuse box. Use a headlamp bulb to load this circuit and ensure it will light the bulb.

b. Pin 9, Light Blue and Red wire, this pin should have battery voltage with the key on, again, use a headlamp bulb to confirm the voltage will light the bulb. This power comes from the brake pressure switch on the master cylinder, when the brake pedal is pressed, the voltage should drop to 0 on this pin. This is a common failure point on this vehicle.

c. Pin 10, Black wire, this wire should be a good ground at all times, use the same headlamp bulb to ensure the ground is good.

d. Pin 5, Light Blue and Black wire, this is the voltage input from the cruise control set switches. When pressing the "on" switch, there should be battery voltage at this pin. If there is not battery voltage at this pin, unplug the cruise servo connector, put your ohm meter across pin 5, Light Blue and Black wire, and pin 6 Dark Green and Orange wire. Now press the "off" button, there should be a closed circuit with the "off" button pressed, if it is an open circuit, it is likely the clock spring has an open winding.

2. If all tests pass up to this point, further testing of the cruise switches will be necessary before condemning the cruise control servo.

 

The horn works

the speedometer works

pins 7, 9 and 10 all tested ok.

the on button sends 12 volts to pin 5.

there are 2.21k, 686 and 124 ohms between pins 5 and 6 for resume, set and coast which is pretty close to 2.20k, 680 and 120 ohms.

the off button doesn't create a short between 5 and 6 as it should. I don't see why that would cause the cruise to not engage.

does it have to be a bad servo at this point? Is there any way to test the servo?