license plate light socket

[bknbronco]

I was looking over the other threads to find the correct bulb for the rear license plate. I found it to be a 1178 which is hard to find. I also found that i could substitute a 68 or a 90.

The strange thing i read when looking over them threads is how the guys were saying that one wire goes to POS and the other wire to NEG. There is no way that would work on mine. Both wires coming off the bulb socket are POS. I believe the bulb is what connects the two wires together. In my wiring diagrams the left running light feeds to the licence plate light and that then feeds to the right running light.

Is there a reason that its wired like this? If i substitute a different bulb for the 1178 will it burn out quicker because of the current that being pulled through it?

Also does that mean that when the license light burns out that the right running light will go out too?

When i rewire should i wire the right and left running light together and just feed the licence light off that and not use that license light as a middle man? I would have a extra hot wire off that bulb but i can clip that or hook them together.

I dont have the 1178 bulb because nobody has them around here so i cant test to see how the bulb works!

Big question is.....does that 1178 bulb complete the circuit between the R and L running lights? Or is
one of them wires actually a ground?

 

[bknbronco]

Sorry about the long post but im used to a bulb with two tits on the bottom being a dual filament bulb. This double tit, single filament bulb has me confused.

Maybe the dual tit is because the tailgate itself provides a bad ground therefore the second wire is a more solid ground?

I think im gona get a headache!!!!!?:?

 

[surfer-b]

Not sure what wiring diagram you have but I have never seen it use the bulb in series, there should be one + and one - wire coming from the license plate socket, and yes splice the + into the running lights wire and the - to the frame

 

[bknbronco]

After further review of the wiring diagram i see a circled letter indicating a connector. So i think that the R and L running lights are tied together at that connector and not at the actual bulb. That would make more sense to me! Im starting with nothing but the wiring diagram and a bulb socket so i have nothing to go off.

I think missing that connector in the wiring diagram is the key to my confusion. Most of the other lights ground through the body so that extra wire may have thrown me a curve ball?

I feel my headache goen away!