Question Cruise and high idle do not work and I don't have a cab brake light

[rjglenn]

Batteries are nearly new, clamps are clean, I've looked at the fuses and none are blown. The manual is not very good in describing what is what or what it is supposed to be where in the fuse panel. I've got some time off coming over the holidays, I'll pull the headliner down and see what's under there, or I'll just get a stick - probably easier to just get a stick...

 

[BIG JOE]

You might try poke'n around in here: www.powerstrokehelp.com ???

Joe

 

[DaveBen]

Thanks for your quick reply.

Kind of doubt it is the VSS, the speedometer works as well as the anti-lock brakes.

High idle is neither OEM or aftermarket, it's not a thing, it's a condition. It is a matter of applying voltage to a particular wire underneath the dash. For the high idle to work there are certain criteria - the truck must be in neutral, the parking brake must be applied, the brake lights have to work, and +12 VDC has to be applied to a wire that is in a marked bundle behind the fuse panel. I found the bundle, I found the wire, I applied voltage, I met the conditions (I thought), but no joy. Since the brake lights also have to work for the cruise control to work I'm seeing a pattern. I'm assuming that the missing third brake light is the culprit and I am asking if anyone has dealt with this before so I don't have to reinvent the wheel. Where do I find the wire for the third light so I can trick the PCM?

The wire that you are looking for is a black wire with a green stripe. Put +12vdc to that and you get high idle. I have a switch on the dash with a wire going to the BLK/GRN STRIPE wire and the other side of the switch going to the hot side of the lighter.

Dave

 

[W4RLR]

Somewhere in the WIKI there is an article I wrote under my old user name of rray32539 regarding up fitter switches for the 2005 F-series. As part of the article it discusses high idle activation using one of the up fitter switches. For the high idle to work, the vehicle must be in park, with the parking brake fully engaged. and power being supplied to one of the wires underneath the dashboard. There's no hardware other than a switch wired to 12 volts and connected to that wire to make the high idle work.

 

[rjglenn]

This was fixed by replacing the clutch safety switch. Thanks to those who replied.