Brake Switch x2 ?

[Eedd]

My 2010 GT man trans has two brake switches on the brake pedal assembly. Why would there be two? I've installed a 2011 Shelby Ford Brake pedal assembly and there is only one place for a brake switch, everything else being the same (except beefier). online ford parts diagrams are inconclusive.
Any Ideas?

Thanks for taking the time to read this.

 

[redfirepearlgt]

The 2011 has a momentary DPST switch. It appears to be a safety redundancy circuit of sorts. With no brake pedal pressed the PCM sees ground on C175B pin 46. When the pedal is pressed, ground is taken away on this PCM signal and 12vdc is applied to the SMJB, Body Module, and PCM to activate the brake light circuit and let the PCM know the brakes are being applied.

I have no hard prints or electronic prints for the 2010. I will assume the two switches on the 2010 perform the same logic as on the 2011. Ford may have chosen a single switch assembly with two pairs of contacts (1 NO and 1 NC) for 2011+ years. The 2005 up to 2009 apparently uses just a single switch according to the paper prints and electronic prints I have available.

It appears from looking at the prints the purpose for this is to ensure the brake pedal switch changes state when the pedal is released insuring the brake light circuit opens back up shutting off the brake lamps. Otherwise a possible CEL (not a limp mode fault) may be generated I am guessing.

Link to 2011 circuit for the brake light switch is below.

http://iihs.net/fsm/?d=711&f=090 - Turn Signal and Stop and Hazard Lamps.pdf&p=3

 

[Eedd]

is it possible for me to link the two separate harnesses to a single switch?

 

[redfirepearlgt]

Only if the switch has two contact sets as in the print. These are two different signals. One sinks the PCM to ground letting it no the pedal is released. The other lets the PCM,body module, and SJB receive the needed 12vdc when the pedal is pressed.
Aside from a likely safety strategy here, this strategy will likely also be needed for disabling cruise control when the pedal is pressed. Again I am going on 2005 and 2011 prints not 2010. So I am making some assumptions here on the 2010 setup. Sorry I cant be of more help. Here is the link to both sets of electronic shop manuals to help you out. The theory of operation should be on them.

http://iihs.net/fsm/?d=0

 

[Eedd]

Thank you Sir. In any event I'll zip tie the two together until I cant figure out how to defeat using both.

 

[Racer47]

My 06 has 2 switches on the brakes and 2 on the clutch. One of the clutch switches operates early in the pedal travel. I assume that is what cancels cruise control. The other one operates at the end of travel for the starter safety switch.

I assumed that one brake switch was for the lights and one was to cancel cruise as well. But I did not look anything up. Just a guess.

I would just use the switch that is from the same location. Keep the other one plugged in and tie it up under the dash and see if everything works like it should.

Where in WI are you eedd?

 

[Eedd]

Thanks racer, that's just what I did. I'm in Appleton, you?

 

[Racer47]

Slinger. Theres a few WI Mustang guys on here but everyone seems pretty spread out around the state.