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There is a problem with my cruise control not "releasing" when I use the brakes. If I use the brakes to slow down a little or just tap the brakes to release the cruise control it will not release and accelerates the vehicle when the brake is released. I have to hit the OFF button on the steering wheel or really stand on the brakes.
My 93 Ranger has started doing this recently. My 85 Van did the same thing since it was new and the dealer was never able to fix it.
Anybody have any idea where to start looking on the 93? I no longer have the 85. It went to junk yard heaven.
Does it just accelerate back to the speed you had it set? If so it must be a design 'feature' as both my 89 van and my 88 RV do that. I have to stay on the brakes for a few seconds for it to stay off.
I looked at a diagram, and the cruise control module uses the same lightgreen wire that the brakes, engine computer, and the rear anti-lock brake module uses. There is a splice down under the dash where this lightgreen wire goes 5 different directions.
If your truck is an automatic, one of the wires goes to a jumper, and then to the cruise control module. If it's a manual, the jumper is taken out and there is another switch in series on the clutch pedal.
It shows that you have a vacuum operated system. There is a vacuum dump valve on the brake arm too. This dumps the vacuum out of the diaphram so the throttle drops out quickly. So if the cruise control is not getting an electrical signal to stop, then once you let the pedal up, the vacuum re-fills the actuator, and it keeps going.
I believe if the set speed and the actual speed get to far apart, the module gives up and drops out. I bet that's what is happening when the other guy holds the pedal in for a time period.
I looked at a diagram, and the cruise control module uses the same lightgreen wire that the brakes, engine computer, and the rear anti-lock brake module uses. There is a splice down under the dash where this lightgreen wire goes 5 different directions.
If your truck is an automatic, one of the wires goes to a jumper, and then to the cruise control module. If it's a manual, the jumper is taken out and there is another switch in series on the clutch pedal.
It shows that you have a vacuum operated system. There is a vacuum dump valve on the brake arm too. This dumps the vacuum out of the diaphram so the throttle drops out quickly. So if the cruise control is not getting an electrical signal to stop, then once you let the pedal up, the vacuum re-fills the actuator, and it keeps going.
Thanks, your drawings and schematics are way better than mine.
So I need to check that jumper and see if it is connected to the module? Normally the bulbs in the circuit hold the wire at ground potential until the stop light switch is activated.
My stop lights work and my truck is an automatic that was rebuilt a month or so ago. I wonder if a wire was removed...
I am not sure if the switch is on the pedal like it was in my 85 or if it is on the MC.
I believe if the set speed and the actual speed get to far apart, the module gives up and drops out. I bet that's what is happening when the other guy holds the pedal in for a time period.
That is exactly what happens if I hit the pedal long enuf or hard enough (speed drops quickly). The system is designed to do that.
Last edited by Torque1st; Sep 23, 2005 at 11:45 PM.
I think I would try to find the module(I haven't a clue where it is though), and find the lightgreen wire going into it. See if you have power there when you hit the brake pedal, and then work your way back from the module.
I am getting old and stiff enuf I hate trying to contort myself upside down to look under a dash anymore. Why couldn't they build these things like an old Mercedes where the dash opens up?