No Brake Lights

[Deuceswild]

I noticed one evening last year while backing the Deuce in the my drive way that I had no brake lights when stepping on the brake pedal. This happend the day before I was putting it away for winter storage and I didnt have alot of time to work on it.
Over winter I purchased a few goodies for it and one of the parts was a new brake light switch, ( I automatically assumed the old switch was shot, WRONG ). I drove it home last weekend with my friend behind me and went to work on it today,, Here's my findings so far,,,,
Bulb filements and the grounds are good.
Installed new switch, still no brake lights , Checked for voltage at the switch,Voltage Present.
Tested old switch with ohm meter, It has continuity
Bypassed the switch, jumped the 2 wires together and the brake lights work.
Right & Left turn signals work properly.
N.O.S. 3 lever light switch installed last year.
No differance in Stop Light mode or Service Drive mode.
The switch is located in the air pack on the lefthand side, and I'm thinking that the switch is not recieving the air pressure signal, ie blocked passage.
Has anyone experienced a problem like this before
Anyway, I'll share more of this experience tommorow night as work continues.
Thanks, Jeff

 

[Recovry4x4]

Remove the left rear glad hand cover and open the valve. Have someone apply the brakes and see if you are getting air there. The air op brake lite switch is tee'ed into that line. If you do have air, maybe the PSI on the Hobbs switch is too high. Just a thought

 

[cranetruck]

"One picture is worth a thousand words"....How about two.

 

[Westech]

you know GM has used a brake light switch like the one on the deuce for about 40 years. there not bad, just when things get old they brake. if you have not changed yours in 5 years or do not know at all , please change it. its like 5 bucks. any 2 prong 1/8 NTP switch will work.

 

[outlaw]

Mine did the same thing
it was the turn signal switch
put on new one and brake lights worked
the brake lights run through the turn signal switch

 

[Westech]

hmm that sounds not right. my turn signal switch is off and my brake lights still work. looking at the wiring harnes its power in to the brake light switch and right to the bulbs out of the switch. think it may have been a fluke.

 

[cranetruck]

I still have the original hydraulic brake light switch. I like the the fact that it will turn on the lights even when there is no air (like in an emergency). As you know, the brakes work to a limited degree w/o the air.
Wonder if the "off-the-shelf" hydraulic switches are pressure rated, deuce brake line pressure runs close to 2,000 psi...

 

[rdixiemiller]

The GM Hydraboost system runs well over 2000 psi if I remember correctly. If you got a switch from one of the pickups with the hydraboost you should be OK.

 

[Deuceswild]

Hey Guys,
Thanks for all the input, I didn't have the time or energy to work on it yesterday after work, It was a long day.

Recovery 4X4, I'm going to do what you recommended and I'll post the results later tonight, Thanks.

Cranetruck, Thanks for the diagram, thats exactly how mine is plummed.

Westech,
I do have a new switch installed.

Outlaw, I do have a new turn signal switch.

rdixiemiller, The brake light switch I bought is supposed to be for a M35 and it looks just like my old one.

Well, to the great outdoors I go to see if I can get this problem figured out. I'll post my findings later tonight and again thanks to all for your input.
Jeff.

 

[Deuceswild]

OK as mentioned earlier I had the new switch installed and no lights, removed the switch and stepped on the brake pedal and I could hear air comming out of the air pack.
Went in the garage and pressure tested new switch at 10 PSI, 20, 30, 40,, all the way up to 130 PSI,with an ohm meter across the switch contacts and no continuity.
Cleaned the old switch out with electrical contact 5 times while working the inside back and fourth, checked for continuity, Got It
Reinstalled the old switch and threw the new one away.

 

[gbooth]

Ok Well now it seems to be my turn with the brake light switch. Lights were working. I was wiring up my trailer for lights now no brake lights. Removed the connector from the switch jumper wire in place Presto Brake lights. Mine are set up the old way the Like in picture #1. What's the advantage for changing to picture #2.

Thanks

 

[Deuceswild]

Greg,
I would remove the switch and clean the pressure side of it with electrical contact cleaner and then apply pressure to it while checking for continuity across the brass contacts. Worked for me.
Jeff.

 

[gbooth]

Yes I am thinking that would be my next thing to try. Its funny and also sad that they worked just last weekend. O well if it ain't one thing it's another.

 

[DanJP2]

Having the same problem. Have lights signals no brake lights. Where is the brake light switch located? Can i get a new one at a local parts store?

 

[bguy193]

When my brake lights quit working i traced it down to the switch plug. It was making bad contact inside the plug, looked as if the last person to pull the plug had pulled it at a sharp angle and sprawled open the female connectors inside the plug end........ Using a small controll screw driver I carefully closed in the female connectors a little and put some dielectric grease in the plug..................worked fine ever since
Good Luck

 

[hklvette]

Having the same problem. Have lights signals no brake lights. Where is the brake light switch located? Can i get a new one at a local parts store?

You can get one at napa, but the electrical connections will be wrong.