'39 truck light switch diagram

TNDoug

Senior Member
I'm trying to figure out the correct wiring for a '39 truck. My understanding is that the switch is different from the '32 to '37's. The contacts are certainly different from the '39 car diagram. I believe that the switch positions are: middle-off, left-parking, tail lights, instrument lights; right-power to floor dimmer, tail lights, instrument lights. Thanks in advance.
 
Have you looked at VanPelt's site? He has the wiring digrams posted. There are three sets of three contacts. One set is the power in and brake light connections, one set is tail lights and dash lights. Because of the floor dimmer switch the third set is parking lights and lead to the dimmer. There are three dead spots between each grouping that is the off position. A triangle shaped set of contacts rotates making the connections or is in the off position. No idea how much difference there is between the 39 std and the commercial/truck, but they should be somewhat similar.

I attached a 38 diagram I drew up in the past, I think the 38 & 39 are fairly similar.
 

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TNDoug wanted these photos of his light switch plate posted.

From the looks of the contacts end, looks like there is OFF (the larger non-contact position) and the PARKING lights in one direction and HEADLIGHTS in the other direction. I'm guessing the small non-contact positions are not used.

On the back the buss with three positions on one side would be the POWER in and BRAKES and the other buss would be TAIL LIGHTS and INSTRUMENT LIGHTS. The two individual connections would be DIMMER feed and PARKING LIGHTS.

All guesses on my part!!
 

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