2000 F-150 Lariat
Bought truck used last year. Working in getting it back to great condition. Cruise is giving me fits. First horn and cruise didn't work. Fixed horn (no relay) under hood. Here are things I have done trying to fix cruise.
- replaced clockspring
- replaced steering wheel switches
- replaced recall harness and switch
- replaced speed servo under hood
- checked all related fuses

Did self test - got the first cruise light when entering. No other lights after hitting any buttons or at end of test.

Parking brake has not been fixed yet. I am very OCD so this annoys the crap out of me. Any help is appreciated.

 

I assume you did a road test as of the moment!
How did you do the testing? May have timed the system out by not operating switches fast enough.
Brake switch may be faulty or miss-adjusted.
What I notice is you report the Cruise light reports you entered the diagnostics but get no further response.
This is a big question.. of why! There should have been a lamp flash report for a failure.
Only time there is no flash is if Power is missing.
.
You did something that should not be done! Replace parts without a proven need.
Doing these things can inadvertently create another issue that causes added confusion.
Sort this out a bit more.
Good luck.

 

what's wrong with the parking brake?

 

Not exactly sure. Either misadjusted or something more. The parking brake light never comes on dash ever. Nor is it actually working.

As far as replacing stuff. These parts are very cheap. Why not. It doesn't cause more issues when part are good.

Cruise light lights up green one time when entering self test mode. This test is super simple. Hold of then run threw buttons once key on within five seconds or it times out. No further light turns on or flashes beyond first time when entering.

 

Break switch had been replaced as of last night. Another very cheap part.

 

Did you prove the brake/stop lights work? High mount also?

 

The brake light on the dash is just that the switch needs cleaning.

your parking brake doesn't work? At all? What have you done to fix that? Sounds like mechanical issues need to be fixed before before items...

 

Just misadjusted I believe. I don't need parking brake before cruise control.

Normal rear brake lights work. Need to have someone check the high mount for me. That has been replaced with LED version. Bed lights work great though. If high mount is not working what does that mean? No bulb to change (LED)

 

​​​​​​
​​​​​​just pulled into a little shopping plaza that I had all glass upfront and backed up to it high mount light does work perfectly.

 

Just pulled into a little strip mall that has all glass front and backed into a spot. High mount brake light works perfectly.

 

I thought I read somewhere that if the brake light was out, the circuit can't complete?

 

No idea but, no matter. My high mount works perfect

 

Replace it with a standard non-LED or add a 100 ohm resistor.

https://www.f150online.com/forums/20...ompatible.html

 

Ok. There is a time when I am giving too much info I think. High Mount light works perfectly. Cruise didn't work from day one I bought it. It had original high mount in it then. It isn't a LED light issue. No CEL and Parking brake light never comes on.

 

Ya all getting off in the weeds.
When the CC is on and engaged, "operating" the foot brake does two functions with CC.
1. The pressure switch under pressure in that condition CUTS power to the CC unit that comes through that switch {when unoperated} to knock CC off.
2. A 12 volt signal is applied (to) the CC through another terminal, does the opposite by "Inhibiting" the CC from further control of the throttle.
This is a double safety mandated by Law as a safety to prevent CC from pulling you into an accident by shutting it down along with the ON/OFF switch control and Acell switch that does not work {as fast} as the brake function.
In some designs the Horn is wired into the system as a knock-off when powered.
While brake lights are a sign the foot switch may not be working, the lights themselves have no effect on the CC.
It would be design foolishness to bring anything extra into it for such an important function that needs fast reaction time and not function because a light was out.
It is still unknown if the system test is being done properly and what the response is to the testing.
All that is being done is replace parts that's not getting it done.
If the CC light comes on when entering the test, it is being powered through the pressure switch and some other fault is the cause.
.
If an after market pressure switch other than a Ford part has been installed, it may be a cause of failure.
The reason is the switch is going open cutting power to the CC unit because the switch is not compatible or designed to work 'to spec' in a Ford CC system. One example is when the engine bay heats up, brake fluid expands a small amount that can open the pressure switch then you have no CC function. This pressure switch has to be sensitive to both high and low (not very low) pressures and to 'live' under very high pressure without failure, it's made special for this application The switch design was done by Texas Instruments Co.
.
You have to take a fresh look at your issue.