Brake lights wont work after bob job

[73m819]

Yeah, I don't know why I forgot the 3-way switch. That's what I get for posting while driving.

I assume "c/bs" means circuit breaker?

He still doesn't know whether he has the air switch or a hydraulic switch for the brake lights, so we don't know if air pressure was a factor or not.

I guess my main point was that touching 2 hot wires together on this truck would do nothing. Take a short wire and touch one end to the positive battery terminal. Now touch the other end of the wire to the same terminal. Nothing happens. The potential is equal so no current flows. It would be the same touching two hot wires together.

In order to short out the brake light circuit, the 3-way would have to be on, and have the brake pedal depressed (with air in the system for the air switch) and have the hot wire go to ground somewhere downstream of the pressure switch. Otherwise, none of the brake light supply wires would be hot and it wouldn't matter if they touched ground or even another hot wire.

In that case, it could be the 3-way got fried or the pressure switch fried, or both. I don't know what the current rating is for either switch, or which on is more likely to survive a dead short.

I think we're back to good old fashioned troubleshooting. He needs to determine if he has voltage at the supply side of the pressure switch. If YES, check the pressure switch output with the pedal pressed, or ohm out the switch to see if it closes with the pedal pressed.

If no voltage to the pressure switch, it's probably the 3-way switch. Do ANY of the lights work? Headlights or turn signals?

In the rear wire harness there is a GROUND wire that is part of the trailer plug wireing, if ALL the wires were cut, I can see someone connecting a HOT to the ground, a hot running/brake light wire to ground can screw up the 3 lever, It did not take much to fry the 3 lever in the m62, the c/bs are designed for overload, a rub short, not a DIRECT short, sometimes the 3 lever will drop out (lights go out, a system quite working), the c/bs cool down, everything then works, other times not, then it is time to replace the 3 lever.

 

[73m819]

OK so ... you guys are gonna laugh (this means some of you are going to yell at me)

but when I bobbed my deuce I had some "friends".... "helping" and they rushed me into just cutting the wires instead of unbolting the mounts and unplugging the lights...

So while one of these "friends" was helping me put it all back together I had 3 hott wires (now you're really gonna laugh/yell) from where the trailer connector was cut off well I had it figured out and he was arguing with me because he's a dill hole. And while I was pushing the brake pedal to show him we had 3 hot wires I'm pretty sure he touched two of them together or something and now there are no hot wires for the brakes

and it was working so well we had our blinker wires worked out and they are also the brake wire's correct? ... so I have tails and blinkers but no brake lights...... what did he screw up are there fuses on this **** thing????

There should be only TWO brake/turn signal hot wires one right, the other left in the trailer plug,

 

[jake1086]

yup I had 2 blinkers 2 brakes and then I had a third that lit up with the brake as well I dunno why? So you guys are thinking the 3 lever is the thing that is shot? And no I didnt have a chance to check the pressure switch tonight.

 

[porkysplace]

I would locate the pressure switch first , one of the 2 wires should be hot with the 3 way switch in the service position ( top lever to the right ) . If no power there then look at the 3 way switch

 

[jake1086]

Back from the dead to put an end to the thread for those curious, the pressure switch was fried, I bought 2 different switches that blew up under hard braking (dont worry it was in my yard) before I found a third that was rated to handle the pressure required at napa. I had it fixed shortly after my last post on here, but never got around to updating you boys, I apologize.

 

[rustystud]

Back from the dead to put an end to the thread for those curious, the pressure switch was fried, I bought 2 different switches that blew up under hard braking (dont worry it was in my yard) before I found a third that was rated to handle the pressure required at napa. I had it fixed shortly after my last post on here, but never got around to updating you boys, I apologize.

Hey what's 2 years among friends. LOL ! At least you did come back to tell us.