1008 No brake lights

[Rich Johnson]

I nearly got plowed on the freeway coming home tonight. A guy slid past me in the emergency lane in the center of freeway so he wouldnt hit me. He was pissed and I was lucky.

I tested the driver side bulb, its fine so I figure that the passenger side is probably ok too.
I took the brake switch out and tested it. It reads out fine with a meter.
I tested the plug to the brake switch and it has 12.8v on one side so Ive got power.
I checked the fuses and they are all ok, I dont know which one would be the brake circuit.
I took a jumper wire and jumped the plug and no joy. I also tested for 12v in the socket without the bulb.

Im freaked out now. I dont know what to do. I know that the wires are all wrapped up in the harness through the dash and then back to the lights, I can only surmise that I have a bad wire somewhere.

Oh yea, its not the blackout switch, the turn signals work and the head and tail ligths.

Any suggestions?

 

[porkysplace]

Have you checked the switch with it on the truck it may be adjusted in to far and not coming on.

 

[top_prop]

Do your other lights work? (turn signals work, head lights, etc?)

 

[Lurchwolf]

It's almost funny, I had the same problem. Thought it was a ground. I tested for it and it was confirmed, so I put a ground strap between the cab and bed, fixed it. But at the same time I found the actual cause. The bed was only loosely bolted to the frame, LOL. Cranked the bolts down and am good to go.

 

[Rich Johnson]

All the rest of the lights work just fine.

I thought about the ground issue so when I jumpered the power plug from the brake switch, I went back and removed a bulb and used my meter and tested for 12v in the socket. No joy.

I am afraid I may just have to take it to an auto electric shop to get it looked at. Now were talking $$$$$

 

[Rich Johnson]

My lights are set up like this;

Tail and turn signal dual filiment bulb. Bottom bulb.

Stop light single filiment top bulb.
Is this stock?

I called an auto electric shop that I k now works on CUCVs and he said its supposed to be stop/ turn dual bulb
And tail light single filiment bulb. Opposite my truck. He says my truck has to be modified and he wants to see it.

 

[Rich Johnson]

My lights are set up like this;

Tail and turn signal dual filiment bulb. Bottom bulb.

Stop light single filiment top bulb.
Is this stock?

I called an auto electric shop that I k now works on CUCVs and he said its supposed to be stop/ turn dual bulb
And tail light single filiment bulb. Opposite my truck. He says my truck has to be modified and he wants to see it.

 

[M1008driver]

Don't know. I would just start troubleshooting the system.

TM 9-2320-289-20
Table 2-4. Electrical Troubleshooting (Con’t)

38. STOPLIGHTS (BOTH) INOPERATIVE (HEADLIGHTS OPERATE)
Step 1. Check 10 amp stoplight fuse. (See paragraph 4-12)
Replace fuse if burned out.
Step 2. Remove and check stoplight bulbs. (See paragraph 4-28 or 4-29)
Replace bulbs if burned out.
Step 3. Check for voltage at orange lead on stoplight switch.
If there is voltage, perform step 4.
If there is no voltage, trace circuit. (See wiring diagram F-14, F-15, or F-17)
Step 4. With brake pedal depressed, check for voltage at white/black lead on stoplight
switch.
Adjust switch for proper contact. (See paragraph 4-16, INSTALLATION) If
there is still no voltage, trace circuit. (See wiring diagram F-14, F-15 or
F-17)
If there is voltage, replace switch. (See paragraph 4-19)
2

TM 9-2320-289-20
4-28. TAILLIGHT AND LAMP REPLACEMENT (ALL EXCEPT M1010 AND M1031).

TM 9-2320-289-20
4-12. CAB FLASHERS AND FUSES REPLACEMENT.

 

[steelandcanvas]

In have seen several vehicles where the brake light circuit is run through the turn signal switch. I'm sure this is done to supply power to the 4-way flashers which in turn flashes the brake light filaments. Just a thought. Maybe an open in the turn signal switch? Do you have a schematic?

 

[Rich Johnson]

I dont have a scematic that I know of, oh but I do know my hazard flashers dont work. Hmmm.

 

[Titanium Soldier]

Not sure if this is set up any different than a civi truck, but i had that problem on mine, the brake light switch tested fine when it was either in or out, but was very intermittent anywhere in between, (like when you just barely tap the brakes) and another time like lurch said.. just a &^$ty ground onto the body!

 

[mistaken1]

I dont have a scematic that I know of, oh but I do know my hazard flashers dont work. Hmmm.

The schematics are in the 20 and 34 and the instructions on reading them are in the beginning of the electrical troubleshooting section.

http://www.steelsoldiers.com/cucv/67999-download-cucv-tms-here-where-download-cucv-tms.html

UncleSam colored them for us:

http://www.steelsoldiers.com/cucv/75505-cucv-wiring-diagram-color-except-m1010.html