help w/ a switch

[bushpilot]

can anyone tell me how this switch works...

lets use "543-21" (to identify the terminals)

i pretty much <guess> that its basically TWO switches in one...
fwiw its the brake light / park lever interlock switch.

can anyone identify which pins would be the 12v source and which
are the ground....

heres what it looks like externally (photo below)
internally it pretty much looks like the top photo...just a bunch of relay/blades

 

[06silvercrew]

Here ya go. This might help.

 

[bushpilot]

sweet ! thanks VERY VERY MUCH !

 

[06silvercrew]

No prob, glad I could help.

Scott

 

[Batcycle]

This is actually called the "Brake Pedal Position Switch". Using your 543 21 designations, here's the wiring. Please note that the wire colors I'm using are for a 2007 F350 so I'm not sure if they match exact to your 2004 but the switch operation will be correct. #5 is your ground wire (pink/orange) #4 goes to the PCM (red/light green) #3 is your 12 volt power which is "always hot" coming from fuse 2.34 (light blue/black) #2 is another 12 volt power also "always hot" coming from fuse 2.18 (light green/red) #1 is your load wire going out to the brake lights and the "Trailer Electronic Brake Control Module" (light green).
The way you have drawn the contacts is correct for their "Normal Position" or "power off" foot off the brake pedal position.
Hope this helps and I didn't over-complicate this.

Jeff

 

[Batcycle]

Bush Pilot, just so you know, your 543 21 designation is actually backwards when you look at the pin designations that 06silvercrew posted. So it would be 123 45 the way you have it drawn.

Jeff

 

[bushpilot]

understood, thanks for the additional details.

I now know which wire controls the
interlock...and i have a PLAN

 

[06silvercrew]

Come on now, dont tease us, what you got in mind? LOL

 

[bushpilot]

Come on now, dont tease us, what you got in mind? LOL

ive had a problem w/ this switch for 2+ years...i havent fixed it
cause its a good theft deterent (and god knows we need all we can get).

if you were to break the park/interlock portion of the break pedal
switch w/ say...a HIDDEN switch...it would be impossible to put the
truck in gear.

in my particular truck the switch is not making contact or failing
on the interlock portion...if i reach down and push the switch enough
to make contact then (and only then) can i shift out of park

 

[Fire1]

The Police Squad cars in the city I work for have done something similar. They wired in a momentary switch that is similar to the old high beam floor button. It is concealed under the carpet and high up. If you don't press it, you can't shift.