No brake lights or turn signals in B61

[skydawg]

Hi,my 1961  B61 has only rear running lights.The bulbs are good(brake filaments).So this truck has just the 6 circuit breakers in the glovebox and no other fuses? Is the brake light switch air operated?The turn sigs don`t work either,so I was hoping for bad bulbs to cure both problems,but no dice.Thanks for any help.

[mechohaulic]

how many wires running to the back tail lights ?? rear  turn signals on tractors  didn't come to be till later yrs. were they working= now don't ??  brake switch is air operated .. front signals working ??  B61 tractor or straight truck.if it's tractor, are brake lights working in light plug ? 

[mechohaulic]

what are you running for a signal light  switch? old square original box or has it been updated ?

[skydawg]

There are 2 wires to the lights w/ dual filament bulbs.The trailer air lines and electric plug were removed in the past.The signal switch on the column looks to be original.So in 1961 they didn`t have rear signals on tractors? I`ve only had it a short time,didn`t get any history,the seller was just flipping.It`s a single axle,ENDT673,Triplex.

[Freightrain]

Ok, the turn signal switch sounds like a Signal Stat 900.  Does it light up when you activate it?  No?  Then you need to trace wiring to find out why it doesn't have power.  Mine had an inline fuse.  Does yours?

 

The brake light switch is typically behind the cab.  If someone removing the air lines, they may have cut it out too?  It is just a small object with two screws in the top for wires.

 

You just have to start with the simple stuff and work through it.

Edited September 3, 2022 by Freightrain

[skydawg]

Thanks,I see the air switch.To test,I need to start and build pressure,then have someone press the pedal and I should see 12v at the wires? Did your truck have rear turn signals from the factory?

[mattb73lt]

Brake lights should be hot at all times, not keyed/switched. Same with your turn signals for the hazard lights. If you've located the switch, test it with a test light to see if one side is hot, it should be. You can also jump the terminals on the switch and the brake lights should light. This sounds like it may be a feed issue if both the turn and brake light don't operate. If you only have single tail lights with brake lights that also operate as turn signals, the brake light circuit runs through the turn signal switch which causes them to flash. Check your feeds first make sure both have power and work out from there. If you have power to everything and you jump the brake light switch, your problem could be your turn signal switch. 

These are just reasonable suggestions and things to try, as we can't see what you're looking at or the condition.

[skydawg]

Ok,I have front turn sigs and flashers.The column switch doesn’t light w/ the signals. The brake light switch has only one wire,though it looks like there is the remains of another post.I’ll try to post a pic.

[Freightrain]

Is the wire on the switch hot?  If not, then the 12v source wire is missing and the reason no brake lights.  That's a simple fix.

[skydawg]

There`s no voltage to that wire.So that switch is missing a tab for a second wire? I don`t see any loose wire that would have gone to the switch.Could you recommend a source for a new switch? Thanks to all who replied.

[HarryS]

I was able to find a replacement switch at the local truck parts store. As far as the missing wire you can use any hot connection for a lead to the switch.

[skydawg]

There`s a 10 post terminal strip at the bottom of the cab,driver`s side,none of the posts are hot.This doesn`t seem right,as the trailer umbilical was connected there. 

[Freightrain]

That post would likely not be hot until you turn on lights or turn signals.

[Brocky]

The brake light switch in your picture should be available at any parts house which deals in truck equipment.. You might want to take that old one with you to get the right pipe fitting thread size???

[Mark T]

A switch that'll work there may not look identical to yours'. Like Brocky said , correct pipe thread size and  a replacement shouldn't be too difficult to find. It'll have two posts for wires but may have a little bit different shape.

Edited September 4, 2022 by Mark T
spelling

[skydawg]

So where would you run a wire for the 12v source?

[Brocky]

32 minutes ago, skydawg said:

So where would you run a wire for the 12v source?

Any hot spot.. Most anywhere!! If your brake lite switch is under the back of the cab probably the starter is the closest. If it is near the foot pedal from the firewall or dash  or a wire which leads to the HOT side of the ignition or light switch..

Edited September 4, 2022 by Brocky

[skydawg]

I got a new brake light switch,connected one post to +batt,the other post to the brake light post on the ten post terminal behind the cab.Now the brake lights come on when air pressure builds,without touching the brake pedal.So there`s air pressure closing the switch when there shouldn`t be any pressure there.I had to disconnect a wire from the switch after shutting the engine off,the lights will stay on as long as there`s pressure in the air tank.I don`t think the new switch is bad,when I installed it the light only came on when I shorted the terminals,with no air pressure in the lines.Any help is appreciated,thanks.The truck is neg ground.

Edited October 6, 2022 by skydawg
added content.

[Freightrain]

That apparrently is not the brake light switch(well it is, but mounted in wrong line).  Looking closely at the picture you posted, the item the switch is mounted to says "tractor emergency".  My guess is that is the tractor protection valve, which is where the trailer hoses attach.  The switch would need to be on the "service" side of that valve(look at other side).  Which would only get air pressure when brakes are applied.  I think that is why it was disconnected from previous owner.

[doubleclutchinweasel]

I'm late jumping in here, and I may be WAY off base.  But, the place the switch is screwed into says "tractor emergency".  Isn't that SUPPOSED to have pressure on it?  Believe that's connected to the "truck tractor protection valve".

Maybe that's not the right location for the switch?  Try tee-ing into one of the actual lines going to the rear service brake chambers?

Again, I may not be seeing the right stuff, and I am no B model expert.  So, don't yell at me too loud!

 

[doubleclutchinweasel]

Sorry, 'Train!  You typed yours faster than I did mine! LOL!

[doubleclutchinweasel]

Just now, Freightrain said:

DCW, see my post above.  You are on the same track as me.

Yeah.  We're singin' the same tune!

[doubleclutchinweasel]

Should be able to move that switch to any fitting anywhere from the treadle valve to one of the tees in the rear lines and get it to work, now that he's got power.

I think mine (R model) was at the treadle valve itself.  But, that can be a pain to work on.  I think they put it there, near the double check valve, so that either the treadle valve or the trolley valve would actuate it.  I also had another switch, I believe, at the parking brake valve which turned on the brake lights when the parking brakes were set. 

It can be located, literally, anywhere in a line that gets pressurized when the pedal is depressed.  Depends on whether or not it's going to have a trailer on it as to how the trailer brake plumbing plays into the picture.

[skydawg]

So I can put the switch in one of the trailer air line fittings that are presently plugged?

[doubleclutchinweasel]

"Service" line, not "emergency" line.  Service line should get pressure when you hit the pedal.