I have an intermittent cruise control problem. I turn the cruise on but when I press the set button, the cruise control light the on the dash flashes briefly and the criuse won't engage. After a few attempts it will work. Othertimes it will work just fine.
What could the problem be? Thanks

 

Most likely a problem with one of the two switches which can disengage it. The BOO (Brake On/Off) switch under the dash on your brake pedal, or the infamous brake pressure switch on the master cylinder (brake master cylinder). I believe there is a clutch switch also on manuals if they are so equipped.

I say infamous since we have the same TI switch that can cause fires in other models. However, they are fed by a high current circuit and ours is fused for a lower current and is unlikely to be a hazard.

You'll probably just have to troubleshoot the two switches to look for signs of intermittent operation, grounds, opens, etc.

 

Thanks, I'll check out those switches asap.

 

Also, have a good look at the connector that goes into the servo and make sure its not messed up -- half plugged in, mudded up or whatever. Clean it up if so. I suppose it could be a problem also.

Last thing would be the steering column harness. Tilt your wheel to a different angle and see if the problem changes. I've heard of all kinds of goofy stuff from the steering wheel harness before on tilt-wheel vehicles.

 

the truck has never seen mud

 

Well on the older Rangers and stuff there was a way to check it. I don't know if you still can.

Put the key in the ignition and hold the on button on your cruise control then turn the key to the on position and then release the off button then you have five seconds to hit the on button. then hit resume then cost then set/accel make shure you do it in this order. For every button you hit the speed control light should flash once for every button then your gas pedal should go to the floor and come back up.

If you hit the set/accel button and the speed control light flashes 2 times you have a defective brake pedal position sensor or a bad clutch pedal positon sensor or the ciruit is defective. 3 flashes - Brake deactivation switch is open or circuit is defective. 4 flashes - Vehicle speed signal is out of range or circuit is defective.

 

Wow, that's pretty cool if its on our newer ones too. I'd never heard of that!

I'm going to give that a try on mine sometime as well, thanks.

And Zach: what do you mean his truck has never seen mud? Isn't it illegal to own a truck and not take it in the mud?! I'm sorry, I'm going to have to report him -- when I get back from the mud in Wharton...

 

so the button trick worked for me. I got three flashes. Now I just have to figure out how to fix it. Any ideas?

 

Sure thing and thanks for searching!

Three flashes condemns the Master Cylinder brake pressure switch, which is the one subject to all the Ford recalls.

Do this: Disconnect the Brake Master Cylinder pressure switch.
Straighten a hefty paper clip and use it to jumper the two pins on the connector you removed. Insulate it with tape so it can't short out and drive it, engage Cruise.

If that works, you need a new pressure switch. Get it from Ford, so it will be the better model, not prone to the leakage/fire issue (the Recall).

 

I probably need a new sensor, but everything works fine in the morning or after the truck has been parked for a long time. It will work fine the first time I drive, but after that, I get nothing.

 

 

What happens if I push the set acceleration button and the light only blinks once?

 

I'm looking to revive this thread - What should I do if the on/off switches respond appropriately, but there is no response during the diagnostic assessment from the RES, CST, SET/ACCEL switches?

Cheers!
Thomas

 

I am in the exact same boat with my 2001. Turn on the key and then OFF light is on. Press the ON and the light flashes but no flash with the other three buttons. I hope someone chimes in soon. If I find anything I will post back here.

 

Slightly different test found for my 97 Ranger.
WARNING:
This test is a key on engine off (KOEO) test that is only conducted in park with emergency brake fully engaged.

Enter self-test diagnostics by depressing the speed control OFF switch while turning the ignition key on, making sure the engine does not start and is not running. The speed control indicator lamp on the instrument panel will flash once to indicate that the speed control module entered the diagnostic mode. Five additional flashes at this point indicate a defective speed control servo. Release the OFF switch.
Press the remaining switches in this sequence: ON, RSM (resume), CST (coast) and SET/ACCEL.
Note:
If the ON switch is not pressed within five seconds after entering diagnostic mode, the module times out and the procedure must be started over.
The speed control indicator lamp will flash as each switch is pressed. Press each switch in the sequence immediately after the light goes out for the previous switch.
Note:
There will be a slight delay when the last button is pressed and the lamp flashes.
A lamp flash with the last button (SET/ACCEL) indicates that the STATIC test passed. If the lamp does not flash with the last button and there are no additional flashes of the lamp, the switch is defective. If the lamp does not flash with the last button, and additional flashes occur, follow the list below for trouble codes:
— 2 flashes: Brake pedal position (BPP) switch is defective, circuit is defective, or brake pedal is applied; clutch pedal position (CPP) switch is defective, circuit is defective, or clutch pedal is applied.
— 3 flashes: Brake deactivation switch is open or circuit is defective.
— 4 flashes: Vehicle speed signal is out of range or circuit is defective.
0.25 seconds after the static test has passed, the speed control servo will carry out a dynamic test automatically by actuating the throttle lever from 1 to 10 mm (.04 to.39 inch) of travel from the idle position. During the dynamic throttle pull, observe throttle movement to witness any binding or sticking of the speed control cable, verify the correct connection of the speed control cable to the throttle lever, and make sure the throttle returns back to the idle position. If incorrect connection or binding or sticking of the speed control is observed, go to the Symptom Chart. If no dynamic pull occurs at the throttle body go to Pinpoint Test F.
Return the ignition switch to the OFF position and proceed to the Symptom Chart.
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I have no information on the Pinpoint Test F nor Symptom Chart.