How to tell which contact is turn/running

[jbgroby]

I order two sockets from LNC and the pig tail are white and black with no others markings. I can trace with a cont. meters which lead is for which contact. I'm trying to find out which bulb filament should be the turn signal vs the parking lamp filament.

Is there a rule of thumb? I think these should be 3057 or 3157 bulbs

[T Smith]

Hook it to a battery and see which one is brightest?

[jtrichard]

the right bulb if yours if OEM style sockets is 1157 heavy duty or 1034 std.duty

[Sharps40]

From my John Lee Jr Thread....."Just so you know...the running/park light filament is always the taller one, its dimmer. The shorter filament is always the flasher, its brighter."

[jbgroby]

Thanks guys, 1157 got it.

[jbgroby]

As usual the overseas market did it backward. Ok I just got new 1157 bulbs and came home to hook the socket leads to a 12 battery charger. The white wire is the lower filament and is brighter. The black wire is connected to the higher filiment and dimmer.
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[Sharps40]

China is on the bottom of the world so perspective....left is actually on the right side and the black wire is actually white. The socket wireing is right, at least down there it is.

[tincan1966]

Almost all aftermarket replacement pigtails have the black wire as "running lights" or tail lights and the white will be stop/turn. Has nothing to do with China or being backwards- it's just how whoever makes it does it.

[Sharps40]

Heck, I thought it was cause they were upsidedown down there. Bet they're at least dizzy mosta the time, seein as how they're always standin on their heads.