cruise control?
Thanks, my first ford diesel, and i am learning from you folks
You're going to be chasing your tail without a scan tool, first and foremost. In truth, I am not sure if the popular "APP" ones even show cruise control data but I know Ford's own does; it shows all switch positions, brake/clutch position, brake pessure switch state, and often will even give the inhibit reason (why the system isn't being allowed to set).
There are a lot of things that have to be in a Goldilocks state (just right) for the system to function.
1. Brake (both service and parking) not applied. There are switches for both. The service brake switch input is not the brake light switch circuit - it's separate internal to the switch.
2. Clutch pedal not depressed. There is a switch for that. It's also a separate set of contacts in the switch.
3. Brake Pressure switch. This is the one located on the front of the brake master cylinder that catches on fire.
4. Speed at least 25 MPH for most calibrations.
5. The PCM needs accurate voltage inputs from the switches on the wheel. Each switch has a resistance value (or open/short in the case of on and off) and it doesn't take much of a circuit problem to alter the voltage drop input to a point that the PCM doesn't recognize what button is being pushed.
A wiring diagram and the ability to use a meter will get you a long way but by viewing actual data you will see what the PCM is seeing and not only is that faster, it can be far more fruitful in your search. There are a lot of things that can cause cruise control to not function and it only takes ONE LITTLE THING to kill it. We can all guess but that's all it is at this point.
Actually not even on a 95-97. The older pickups must see a ground signal on the brake switch input before cruise control will function. The 99-up don't as the PCM either gets the ground internally or ONLY needs to see the 12v input on brake application (I don't know which one it is and it doesn't really matter since it just works). Flatbed installations using the trailer wiring for light functions on 95-97 (or using LED brake bulbs) are most susceptible to "needing" the 3rd brake light to function as there is no filament in the LED to give a path to ground when the lights aren't illuminated and the trailer wiring doesn't "feed" back to the PCM unless a trailer (with incandescent bulbs) is attached.
In addition to what Cleatus12r has told you in post #2, this thread has some good information that may be of use to you: https://www.ford-trucks.com/forums/1...or-cruise.html
If you have not seen it yet, there is a sticky thread at the top of the main page called "7.3L PSD Tech Folder" which contains a bunch of useful information. Check it out here: https://www.ford-trucks.com/forums/1...-7-3l-psd.html
Keep us updated if you find the problem or not!
You're going to be chasing your tail without a scan tool, first and foremost. In truth, I am not sure if the popular "APP" ones even show cruise control data but I know Ford's own does; it shows all switch positions, brake/clutch position, brake pessure switch state, and often will even give the inhibit reason (why the system isn't being allowed to set).
There are a lot of things that have to be in a Goldilocks state (just right) for the system to function.
1. Brake (both service and parking) not applied. There are switches for both. The service brake switch input is not the brake light switch circuit - it's separate internal to the switch.
2. Clutch pedal not depressed. There is a switch for that. It's also a separate set of contacts in the switch.
3. Brake Pressure switch. This is the one located on the front of the brake master cylinder that catches on fire.
4. Speed at least 25 MPH for most calibrations.
5. The PCM needs accurate voltage inputs from the switches on the wheel. Each switch has a resistance value (or open/short in the case of on and off) and it doesn't take much of a circuit problem to alter the voltage drop input to a point that the PCM doesn't recognize what button is being pushed.
A wiring diagram and the ability to use a meter will get you a long way but by viewing actual data you will see what the PCM is seeing and not only is that faster, it can be far more fruitful in your search. There are a lot of things that can cause cruise control to not function and it only takes ONE LITTLE THING to kill it. We can all guess but that's all it is at this point.
Thanks
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Depends. Again, I don't know how inclusive things like ForScan or Torque (the more popular low-buck options) are and if they show cruise control data. I use either of them regularly just because of the user interface and portability. However, I KNOW that the Ford NGS scanner includes this data and I use it specifically for things that aren't shown on other scanners (like electronic shift on the fly problems; ESOF 4x4 data). I've had AutoEnginuity for about a decade now and would have to assume that it's been better than 5 years since I've used it for diagnostics although it did do a PATS relearn on a 99 Explorer about a year ago that the NGS wouldn't.
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There was a Ford Recall due to fire potential and they installed a fused wire off the brake pressure switch. Mine had failed and once replaced the CC has worked fine ever since.
I'm going through this process in reverse because I have decided to add CC to my 2000. Apparently most of the wiring is there, the brake pressure 'secondary safety' switch is not.
Start the old way, get a wiring diagram and measure voltages, grounds and continuity.
@cleatus12r once you/ve seen the data you'll have to break out the multimeter anyways. It's not that complicated a circuit, so you might as well break it out from the start.
Understood that the connector is there, thank you - I'll look again because I had not seen it. If that is the case, it would just be a matter of installing the switch and the bracket or am I mistaken? Of course, the clip would also work.













