Deuce brake light problems

[drthunder33]

Ok, here's the problem. No brake lights. This seems to be a common problem and the search feature brought me hundreds of pages of helpful advice. Alas, I still have no brake lights. The headlights, blinkers and parking lights all work.

Here is what I've done.
Replaced the air switch with a new one (updated) from odiron.com.
Checked the connections at the tail lights
Checked the bulbs as well as the ground connections.
Pulled the blinker switch, opened and inspected
Pulled the light switch, opened (p.i.t.a.) and inspected.

I have the wiring schematic that Cranetruck posted back in '06 and it looks as though I'm at the end of my rope.

What am I missing. This is driving me nuts!

 

[renovate7]

I just went thru this and found a bad bulb, thankfully. Get a test light with a needle type probe and start at the back end and work forward until you find power. You could also start at the front and work backward. You stick the needle right thru the insulation on the wire. I think the turn signals and brake lights use the same wire to the rear end so if you have turn signals the wire is ok. I also might start by taking the big plug off the back of the 3 lever light switch and jumpimg from F the hot input to the brake hole, don't know the letter. That will let you kjnow if there is a problem in the switch. I found that my bad bulb looked ok, the filiment was intact but it was bad. Have you tried putting in a bulb you know is good, like one from the front light?

 

[ENCS_DEI]

Stupid question, but with the air operated switch update do you have the air tanks charged before tesing?

 

[WillWagner]

Don't poke thru the wire, unless you want corrosion issues. You live in Mi? Does it snow and do they salt the road? If you think you have an issue now wait till you poke and drive on salted roads a few times . Use a DVOM. If you jump across the brake switch, do the lights work?

 

[m-35tom]

this is a very simple thing to fix. turn the switch to service brake and see if you have power on one of the wires to the brake light switch. if yes the problem is in the rear of the truck. if no do the turn signals work? if yes replace the turn switch. if no check wiring from turn switch to light switch. this is about the simplest wiring you will ever encounter, just apply logic. brake and turn use the same bulb, if turn works then all wiring and bulbs are ok.

 

[Recovry4x4]

Also triple check your grounds. There are seperate grounds for seperate bulbs in the rear lights. Clean the area behind each mounting bolt thoroughly and use paint piercing washers to insure your grounds are good.

 

[drthunder33]

Grounds are all good. I did the check at the brake switch with the light switch on "service park" and "service drive" and have no juice. It looks like I'll be needing a new blinker switch as well as a new light switch ( I lost some parts when I opened it up for inspection). Hopefully something does the trick.

 

[Manstein]

I have had two seperate brake light debacles. The first was a housing ground at the frame between the left brake light housing. The second was much harder to find. It turned out to be a loose pin in the connector where the front and rear harness link up. Start tracing with your multi-meter at the rear and work your way forward.

 

[drthunder33]

Problem solved.

Replaced the 3 lever switch that I lost parts to.
Replaced the blinker switch with an updated model.
Started it up, let the air build up and VIOLA! BRAKE LIGHTS!

Thanks guys for all your help.
Without it I may have completely lost it.

 

[jwaller]

congrats on fixing it. makes you feel good.

 

[Somemedic]

Blinker switch.. this is the little jobby thats on the steering column that you flick to the left and right when you want to turn? NOT TO BE CONFUSED with the flasher control unit? Brake lights arent working and up until the other day the turn indiactor lights were working but now dont. Get a new switch not a flasher unit, correct?