Smoke Em All
Full Access Member
Thanks dude!!There is actually a marking (usually) somewhere on an LED. But the easy way is that the positive is generally the longer leg.
You can always solder one LED to the board using the longer leg as positive then go back and plug the harness in and see if it lights up. You'll find out soon enough which is correct polarity (given that you soldered correctly) and then you can keep on going with the rest of the LEDs.
Sent from my iPhone using Tapatalk