96 f250 diesel - cruise control problem
 

This truck is new to me. It runs fine but the cruise control doesn't work. I have a Haynes manual that says it's too complicated for me to tackle but I'd like to at least see if there's continuity etc. Can anyone tell me where the cruise control box is on the vehicle and what it looks like. That'd be a good start eh? Any other info would be appreciated.

Try posting in the powerstroke desiel section, but the book is right it is very complicated, the powerstrokes injectors are all controlled by a computer, so i would think the crusecontroll is linked to the computer, not a mechanical actuator like a gas job. did you check the clock spring under the steering wheel??? that will cause the cruse not to work,

Clock spring? What's that? Something in where the cruise microswitches are?

I recently experienced a similar problem with my F-150. You should read my posting dated 02-04-2004 for my solution named DRH- F-150 Cruise Defect. If the cruise disabling switch is not the problem you can check for power at the cruise servo by unplugging the terminal block at the servo and testing pin no. 7 for voltage with the ignition switched on. If you do have power and the disabling switch checks O.K. then the buttons on the steering wheel may need cleaning(see previous postings) or worst of all, a bad servo. Good luck.

DRH, its a computer controlled powerstroke, no servo in this rig,
And the clock spring is under the sterring wheel, it allows the connections for the horn airbag and crues controll, theese wear out, and cauuse stuff not to work, there are a couple on ebay that are new and pretty cheap, and like DRH said could be a dirty switch,

ATC-250SX may be may very well be right about no servo on a PSD. However, I know it has a Cruise disabiling switch on the end of the master cylinder. I used A 97 PSD to test said switch against mine. The 97 PSD switch checked good, mine was bad. If there is any evidence of brake fluid on the outside of this switch the continuity of the switch should be checked. The switch should show a closed circuit when the brake petal is not depressed. It will show a open circuit only with the petal depressed if working properly.

Oh ok i see, that make sense, cruse would "Think" you had the brakes pressed down if the swith was faulty. that makes sense

Thanks for the ideas guys. I'll check for a disabling switch. The switches under the horn cover thingy "look" good but I'll check for continuity. Still don't get what the 'clock spring is' but maybe I'll spot something. Thank you both for your help.

The clock spring is the part under the steering wheel wich connects the buttons on the wheel to the steering column,

Well that was it DRH. I checked that cutoff switch with an ohmmeter and it showed several megohms resistance. So I pulled the connector, shorted it across and the cruise worked. Just ordered the switch (which is $28 at the dealer - NAPA can't get one) so should be up and running pretty soon. Thanks for taking the time to respond.

Glad it worked out for you. NAPA did not work for me either, only FoMoCo. If you make a quick changeover you will not lose any brake fluid. I also learned something about this problem. DRH

DRH/ATC_250SX,

Just FYI. On a 97 truck, even a PSD, the cruise control is actuated by a servo. Granted this is not the old style vacuum actuated servo, but a electronic servo. I have the same part on my 95. This is the device that pulls and holds the cable going to the throttle body. It is controlled by the computer to tell it how much to open and when, which is why you have the electrical connector going to it. There really is no way to test this, just better of replacing if you find nothing else wrong in the system.

Granted this was not the problem in this case, just wanted to let you know that the PSDs do in fact have control servo for the cruise control..

Oo.