Identifying Positive, Negative of LED unit

[john2k]

I have a car LED unit that goes on the side mirror. The unit has a 2 pin connector. Is there any way to determine which connector is positive and which is negative without randomly trying it and risking getting it wrong way round?

Also, is there any way to determine if the unit has it's own internal current limiting resistors or a driver of some kind? If it doesnt, i dont want to feed power to it that's not driven or limited

Thanks

 

[BobK]

What DO you know about the LED? Forward voltage, operating current?

Bob

 

[john2k]

What DO you know about the LED? Forward voltage, operating current?

Bob

NOTHING AT ALL (LOL)

It's one of those indicator LED units that have lots of LED's inside.

 

[Rleo6965]

If its really a unit. It's surely have a built in current limit resistor. Don't worry about the polarity. LED don't conduct or lit on reverse polarity.