The Stovebolt Site Forums The Shop Area The Electrical Bay Park to running lights

Hi - wondering if anyone can offer some advice. I have my 37 gmc electrical back to spec aside from installing turn signals and a right tail light. I want to have my rear park lights on as running lights when the headlights are on. I've read the tech tip showing a jumper from headlight to park lights at the back of the switch, but wanted to still have my park light only position on the light switch work. I was wondering about a diode which I have not used before. I was thinking a 6v diode but not sure.

I do not know about 1937 Chevy's but my 1935 Buick had a tail light with a dual filament bulb socket with a dual filament bulb.

Pull the light switch half way front parking lights and tail light would come on.

Pull the light switch all the way headlights on, front park lights off, tail light still on.

If your tail lights are going off then they are being fed off the same terminal as the parking lights. This is why your tail lights are going off when you put your headlamps on.

Something is wired wrong at the switch, tail lights are fed from the parking light circuit which is wrong.

Thanks for the reply - I think you're right. I think maybe there is something wrong with the light switch because no matter what position I put the wire in I can't get the tail lights to stay on with the headlights unless I jump it. Can anyone tell me what the delco part number is on the light switch for a 37 chev/gmc 1/2 ton? Mine is 1994011 which may not be correct

The part number for your light switch should be 1844903, which is the same for 1936. The GMC switch is different than the Chevrolet switch.

Thanks Dunfire. I'll start looking for the right light switch. This one works well enough to get through inspection at least.