m925 w/w brake light issue

[2brothersjunkin]

Hello everyone. Im new to the military truck world and this site. Been quite on here for the most part because ive been able to find anything I needed just browsing the forum. My brother and I own a scrap iron business. We own a 66 Kaiser and just bought a 83 am general m925 w/w. The issue we are having is the brake lights dont come on. Both filaments come on on the running lights. We ran a wire tester over all the wires and the trailer hitch and when you press the brake pedal nothing happens. I was reading another post and someone else's issue was solved by replacing the turn signal switch. Any thoughts or suggestions? Thanks in advanced for the help!!

 

[Gunzy]

You need to check the brake light switch under the truck on the frame about half way back (check TM for location). I assume you have T/S working. Just unplug the two wires going to the switch and short them together, if the brake lights come on replace the switch. It is an air pressure switch and prone to failure.

 

[doghead]

You could swap out the turn signal units and see if that solves the issue.

 

[DanDan]

I found that a 'field repair' had been made to my brake light wiring so I just had to redo the connection. Do the blackout brake lights work? Check them as it may help diagnose the problem.

 

[2brothersjunkin]

Do you have a picture of what the brake light switch looks like?
And honestly not sure if the black out lights work... not sure how to use them. I dont know much about these trucks

 

[doghead]

Start by downloading the TMs, and reading the basic operators manual(ends with -10).

 

[doghead]

There will be a picture of the brake light switch in the parts TMs.

They end with " P "

 

[olly69]

A whole lot to learn...

Do you have a picture of what the brake light switch looks like?
And honestly not sure if the black out lights work... not sure how to use them. I dont know much about these trucks

I hear ya. I bought one in Feb, and I feel like I am 16 again trying to learn how to drive & do simple things like change the oil on dad's car.... I can relate to the feeling, wish I had some MV owners in my area like some of these guys on this forum.... but what a great help these guys are!

 

[2brothersjunkin]

Is this what the brake switch would look like? I looked in the tm and believe thats right but not certain. Its on the driver side just past the first set of marker lights


Edit: ok I do believe that was the problem just gotta get a new switch

Final edit: got it working! Thanks for the help!

 

[Piper Cub]

What did the problem end up being? Loose wire? Dirt in the switch?