5 pin push button switch with LED AC wiring question
The easiest way to find out if the LED already has a suitable resistor inside the switch for a 12 Vdc supply is to assume that it doesn't.  

Add a suitable resistor in series, power the LED &amp; resistor from a 12 Vdc power source, then measure the voltage across the LED terminals in the switch.

If the LED does NOT have a suitable resistor internal to the switch, the voltage across the LED terminals will be anywhere from 1.7 to 3.4 Vdc, depending upon the colour of the LED and the LED will be fairly bright.

If the LED does have a resistor inside the switch body, the voltage across the LED terminals will be substantially higher - 6 Vdc or more and the LED will be dimmer than it should be.