Technical Grounds for a problem

So hey, what is the story on mid sixty's C10's wiring? I am trying to connect new LED parking lights up front and the plug n play connectors are not working. The new-wired 1157 buckets don't seem to connect well. The new barrel and pin measurements don't match my Chevy. So I decided to clip them off and solder the connections. Got everything ready and I find the ground is white on the new led lights??? I thought it was black. And worse, the new led lights have three wires: park, signal, ground and the old wiring has two wires: black and white.
Do any of you have experience you can share? Do I just splice the red and black together? This was supposed to be a simple deal.

 

Sounds like you are switching from single filament bulb holder to dual filament. If you want park lights, you can run some wire to tie them in with the tail lights perhaps. Or to simply run the turn signal portion, just leave the park light wire off, and only connect the signal wire to the terminal on the new socket that activates the "bright" filament. You can pre-test this on the bench with a battery and some wire.
On my ol' Furd F100 project, I also installed new bulb holders. Regardless of wire color, the wire attached to the housing is the ground. I also ran a separate ground wire from the housing itself to a ground connection. Yes, overkill. But there really is no such thing as an overdone ground in my mind.

 

Happens lots with universal wiring parts, color codes aren't the same. Your original parking lights were grounded through the body. (housing of the parking light). The additonal ground wire ensures you won't have ground issues.

 

S 'never simple!! (Even when "they say" it's simple.)
I would hook it up temporary until you find which wire goes where. After......maybe change color on ground wire to what matches every other ground.
50's/60's and older wiring is very basic ...hard to screw it up 'permenantly'.
Do what 1000's of hot rodderz have done in the past.........smoke test it til you figger it out.
That's all I got........
6sally6

 

on the original lights, ground is through the housing, there is not a wire for it.

In some of the Direct Current (DC) electrical wiring world, Black is "hot", and White is "ground" (or Neutral). Just like in Alternating Current (AC) wiring in houses, etc.

I don't know what the LED stuff is color coded to, it probably depends on who made it, and what the original application was, if any.

I do know that normal light bulbs still work fine. And that getting the sockets in 50+ year old parking lights and tail lights to conduct ground properly can be a bitch.

So...don't be surprised if white is ground, and red and black are the two light "hot" wires. You'll have to provide your own ground wire, and making it get real ground on the hood of an old truck can be fun. they originally had a ground strap from the body to the hood on those trucks, they're usually missing.

 

Thanks a bunch guys. That verifys what I was thinking. I'll just alligator clip some test wires and prove it out. I was going to run a new ground wire to the fender anyway. I don't trust the hood as a ground source.

 

Every time for a split second I have this moment when putting the battery back onto to the travel trailer.

 

A conventional 1157 also as three wires, one of them is not so wiry, though.

It is not uncommon for LED lights in automotive/trailer applications to have white for a ground.

Not every US automaker uses the same color code, and overseas ones are just as variable.

 

Most 1157 bulbs have no external wires at all, just a cylinder shaped thing for the ground contact, and a couple hemisphere shaped things for the two power contacts. But they do have wires inside.

 

That's what I said.

 

As already mentioned, a good ground strap between the hood and the fender should ground the hood as well as anything. Also remember that LED lamps are polarity sensitive. LEDs act as a one way electrical check valve. Incandescent lamps don't care which way current flows thru them.

 

Quite a few now have bridge rectifiers inside and a regulator, meaning you can plug them in backwards and they still work. Clever stuff!

 

Thanks. Clever, indeed. The last ones I worked with in an OT retrofit third brake lamp sure didn't have the extra "goodies" in them.