I replaced my headlight switch with a Standard DS357 since the original one gave up and I had no interior lights at all.

The new switch would only light the dash lights if I held the stalk in a certain position. If it moved it slightly the lights would go out.

I thought I had a bad switch, so I bought another of the same brand. This switch had the same exact issue. I doubt both switches had the same defect, but I guess it’s possible that brand just sucks.

The harness that plugs into the switch is good, contacts are clean. I was able to jump power from constant power (red) to the interior lights (tan). All the lights came on like they should. Fuse is obviously good (I checked anyways), since the lights came on.

Can anyone think of an issue besides the slim chance both of these switches were defective? I can’t dissect the switches and autopsy them because they’re riveted shut.

 

Check the switch with a meter, It's possible there was a bad batch of them. And especially if it is a low buck version of the switch. Look on rockauto and see what other brands are available.

 

I’m going to do that this morning. Never occurred to me I would have to test my brand new switch with a meter…

 

So I tested the original switch that came out with a multimeter. Resistance was good at B2 to I terminals when I pulled the stalk, mechanically the switch did what it should.

I threw it in the truck and it blew the 30 amp fuse in cavity 8 for exterior lights. Put a new fuse in and the interior lights came on no problem!

I haven’t had that switch in there in months, so who knows what electrical issue I might have corrected in the mean time.

Someone on another forum mentioned the switch itself needed to be grounded. There is a male connector on the switch itself for a female ground plug.

The switch wasn’t grounded when I originally took it out, it isn’t grounded now, and there’s no hanging ground plug laying around. So what is that ground plug for out of curiosity? I thought maybe for the dimmer potentiometer?

 

the ground is for the cab light. if it is not grounded then you just can't turn on the interior cab light using the switch if it even works. a lot of the time people don't have them working because of bad door jamb switches or the fact they require a special bulb.

 

Thank you. I changed the dome light bulb and it works just fine with the doors opened and closed. I’ll ground that tomorrow morning and see if I can get the dome light switch to work.