OK, I solved my battery draining problems. Next I want to get my cruise control working, I don't think it is even turning on, as I get no indicator on the panel. Any ideas where to start?

Thanks, my first ford diesel, and i am learning from you folks

 

Ford does things a little differently. The "CRUISE" light (or the little green speedometer icon for the 02-up) does not come on until the system is actually set at a speed - unlike other makes that let you know that the system is simply on.

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.

 

Your third break light is also tied in to you’re cruise control...

 

Not on a Superduty.
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.

 

@bewildered 7.3 , welcome to the FTE!

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!

 

ok, good to know, my generic $50 OBD2 scanner doesn't show anything. I'm sure there must be better scan tools out there, do you have a favorite?

Thanks

 

I am using forscan to try and track my issue down.

 

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.

 

Thanks for this. found one on ebay. I'm back after an 800 mile test drive. ebay auction will close in 30 minutes, and I may have the NGS scan tool. I've also read about water leaking from the windshield causing problems in the fuse box. Mine leaked a lot in a heavy rain squall a couple days ago, so I need to look at that.

 

On my 2000 F250 it was a factory add on circuit near the master brake cylinder.
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 am not sure a scan tool will help.

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.

 

Here's a picture of the assembly from Amazon:

 

Seeing data that says whether the clutch switch is on or off, the brake switch is on or off, the brake pressure switch is on or off, or even which button is being pressed on the steering wheel isn't helpful? Once the missing link is determined it becomes apparent which circuit to begin chasing.

The brake pressure switch on the master cylinder is a redundant safety switch used in case the brake on/off switch malfunctions or loses 12 volts. It can be bypassed by installing a minifuse or paperclip into the connector (that IS there behind the airbox) if a person is capable of knowing what the "OFF" button on the steering wheel is for. The switch is normally closed so simply shorting across the connector will function as though the brakes aren't applied.

 

Wait wait wait. @jimjokjv do you have a link to that on Amazon? 8W7T 14A411 E5595 I think?

@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.

 

All I could see on mine when taking a quick look was the 14A411 so not 100% sure this is the exact same harness. Just wanted to give an idea of what to look for.