Brake light switch location

[Richard Davis]

I have lost the brake lights (and cruise control cancel) on my '06 Monterey.  I am assuming there is an air activated brake light switch somewhere.  I have searched the forum for others with the same issue, but nowhere do I find a definitive answer for the location of the switch.  The air brake hose connections are way up on the outside of the firewall (right through the firewall in front of the brake pedal) , but I can see no switches with electric connections.  So, can anyone provide me with the location of the switch on my Monterey so I know where to look?  Thanks.
Richard     

[Carl Boger]

Richard,

If your coach has air over hydraulic brakes there is a round disk shaped air valve that threads into the air part of the system.  From there it has wires that fit to two screw on terminals.  It is hard to see it, but it is under the drivers foot area kind of buried in the frame.

If you have a different set up this may be totally different from yours.  Hopefully this will at least give you a place to look.

[Richard Davis]

Carl
Thanks for your response, but the 2006 Monterey has air brakes only.
Richard

[Steve Huber Co-Admin]

Richard,
Have you looked under the dash at the very top of the brake pedal bar? There will be wires coming from it if it is locate there. This is if your brake pedal is similar to the one in your car (Roadmaster chassis). The older Magnum chassis coaches had a brake pedal the similar in shape to the accelerator pedal. Then it may be outside the cabin area. Not sure which the 06 employed..
Steve

[Richard Davis]

UPDATE!
I found the brake light switch.  It is located directly behind the drivers side headlight assembly mounted into a "U" channel frame member hidden behind a bundle of wires (I followed the air lines from the back side of the air brake assembly on the firewall).  The bad news is there is nothing wrong with it.  It has 12 volts on one side of the switch and the switch shows proper continuity when the brake peddle is depressed.  So, I will have to chase the problem thru the relays in the front run bay. 
Richard

[Steve Huber Co-Admin]

Richard,
The 06 Monterey wiring diagrams in Coach Assist show the following;
Pg 5: Brake relay K25 sends brake switch signal to brake lights. (However Front Bay layout on pg 16 shows relay as k24).
Pg 13: K4 senses both CC from smartwheel and brake light signal and sends signal to ECU to turn off CC.
Both are in Front elec bay. IMHO easiest way to check is to substitute known good relay.
Good Luck, Steve

[Richard Davis]

FINAL UPDATE
I finally found and solved the problem.  There was a break in the power wire to the air brake switch.  It would test at 13 volts with no load, but would drop to almost nothing when any load was applied.  The problem was caused by an inadequate support of the wiring bundle that comes out of the front run bay.  The weight of the wiring bundle was actually hanging on the two wires to the air brake switch.  Eighteen years of bouncing along on bad roads and that weight pulled the wire in two somewhere inside the bundle.  I ran a new wire from CB18 out to the brake switch and all is now good.  So, a warning to others: that is a heavy bundle of wires that exits the FRB.  You might want to check that it is adequately supported.
Richard