Wire woes

Lugnut · Post by **Lugnut** » Sun Oct 09, 2005 3:33 pm

Dear board, I am trying to get the lights working on my GMC 352,SWB. I am using the original harness when I can, as it looks to be in good cond. I have the rotory switch. With the power switch on I checked all the terminals on the rotory switch with a 6V tester. About 3 did not show any juice. could this be why I have no front lights? I ran a wire from a hot terminal on the fire wall to the little screw-on panal where the 3 wires fasten. Lo and Behold the lights came on. But a check of that terminal shows no juice with the switch in "HL" position. Do you-uns think I need a new rotory switch???

armydriver · Post by **armydriver** » Sun Oct 09, 2005 6:05 pm

That would be my guess. Remember these switches have just contacts that can get corroreded and that insulates the power and pretty much keeps them from working.
New rotary switches are available and worth the money to eliminate any future problems. The rotary switch for the jeep is the same as for the CCKW.

Tim Baltz · Post by **Tim Baltz** » Mon Oct 10, 2005 6:04 pm

Check the dimmer switch, the wire runs from the switch to the dimmer then to the terminal block. use the TM to find the right terminal on the switch and check it they. Armydriver maybe right also as I've had this problem with a push-pull switch. Hope this helps.

dr deuce · Post by **dr deuce** » Mon Oct 10, 2005 7:10 pm

A couple terminals are for the brakes. They control what the brake light switch is connected to, so they only connect to each other during various positions:

S = from brake switch
SS = Service Stop
BS = Blackout Stop

SW connects the power to the other side of the brake light switch except in the all off position.

If you are running 12 volts, you can rewire the ignition switch feed to the SW terminal on the light switch. By doing so, when the switch is in the all off position, (push-pull all the way in for example) you cannot start the engine. Very useful on lever action ignition switches....

Lugnut · Post by **Lugnut** » Wed Oct 19, 2005 6:20 pm

Thanks guys.

armydriver · Post by **armydriver** » Thu Oct 20, 2005 7:48 am

That is what makes this site so great. Experts on CCKW's are few and far between, but if we all pool our knowledge we can help each other out.

Craig · Post by **Craig** » Sat Oct 22, 2005 2:13 pm

Most of the light switches on WW2 vehicles are quite simple by design. With a little patience one can dis-assemble the switch and return the switch to servicable condition. Most of the time it's just a matter of cleaning the contacts. over time they will corrode. I've done this serveral times over the years with very good results nearly every time. It's not difficult, will save you money, and in the end you will have the original switch which is always better than a re-pro. Just my two cents.

The GMC CCKW

Wire woes

Wire woes

Lights

Wire woes

Push pull switches