No brake Lights

[ltlbo]

My fellow Deuce lovers: I have a 1988 M35A2 that failed state inspection because of no break lights. The rear running lights and turn signals work fine but no break lights. Can any give me a good starting point or possible ways to fix this issue? Thanks

 

[donnerwetter58]

The brake light switch would be the next item to check.
Switch should be normally open and have continuity when brakes applied.

 

[ltlbo]

Is the switch hard to locate or replace?

 

[frank8003]

Is yours on hydraulic side or air side?
Brake Light Air Operated Switch, M35/M54/M809/M939 etc, 11602160


Item# 11602160
$45.00

Product Description

Air operated switch for brake lights (also called a stop light switch). For many Military truck series such as M35, M54, M809, M939. Switch closes at 5-8 PSI. P/N 11602160, 7005. NSN 2540007896192. Made in USA.
I could post the TM but you already know how to find replacement instructions.





Here it is anyhow, TM + WP.
View attachment air pak stoplight switch replace.pdf

 

[M813rc]

This will also be a valuable resource for you - http://www.steelsoldiers.com/forumdisplay.php?113-The-Deuce-TMs

All of the military manuals for the M35 are in there, and cover in detail any repair you might ever consider for the trucks. Once you familiarize yourself with them, they answer most questions, and also can clarify answers given by other members.

Cheers

 

[ltlbo]

Air side

 

[cattlerepairman]

Air side

NAPA has civilian switches that also work if you do not want to wait.
http://www.steelsoldiers.com/showthread.php?130915-Air-stop-light-switch-issue&highlight=
or metal, if you don't want the white plastic: http://www.napaonline.com/Catalog/C...toplight-Stop-Light/_/R-MBIBE13250_0214431597 (thanks rustystud and smokinyoda)

 

[dmetalmiki]

Why not brige the brake light swith wires, then you will (would have known) for sure the problem. Switch or otherwise.

 

[Katahdin]

Were the air tanks fully pressurized when the inspection took place?

 

[Big Dumb Truck]

Silly questions, did you have the light switch on the dash turned on?
If both lights aren't working I would start at the brake light switch as mentioned above.

If only one light isn't working then I would look at the turn signal. When you put the turn signal on, it has to turn off the brake light. Otherwise it wouldn't flash. The contacts in the turn signal are riveted to the printed circuit board. The rivets can come loose and let the contact rotate out of position. It can even contact the adjacent contact and give off some strange voltage readings.

When you put the light switch on, one of the wires at the brake light switch becomes hot. It should be 24v. The other wire goes to the turn signal switch. From the turn signal switch the power is distributed to the brake lights.

 

[The King Machine]

Why not brige the brake light swith wires, then you will (would have known) for sure the problem. Switch or otherwise.

^
this.

If it turns out the switch is functioning, check the turn signal switch after. Take it off, take it apart, clean the contacts.

 

[steelandcanvas]

Probably should have done a pre-trip inspection and found this problem before trying to pass a state inspection.

 

[Tracer]

When my brake lights went out several years ago it was the brake light switch.

 

[ltlbo]

I got the new suggested switch and its not what I currently have......is there another style other than this one?

 

[ltlbo]

Not the same switch I have.....is there another version?

 

[The HUlk]

Not the same switch I have.....is there another version?

Perhaps post up some photos

 

[cattlerepairman]

Not the same switch I have.....is there another version?

Yes, pics please. There are variations, some full metal, some metal and bakelite (don't like those). The shape does not matter, as long as it has the right thread. You did jumper the brake light switch wires to check that the lights themselves and, by extension, the circuit through the light switch work?

 

[ltlbo]

Which one is the break light switch?

 

[ltlbo]

 

[phil2968]

He has a dual system brake truck.