How did you guys know the polarity of the bulbs and which way to put into the socket that twists into the cluster?

I just fried the plastic ribbons in the back of my cluster because I did trial and error with the bulbs. It started smokin within 5 mins of turning the car on.

So how do we determine which way the bulbs need to go into the sockets? They're led bulbs.

 

Bulbs have no polarity. I also smoked one of my ribbons. My best guess was that I did not have it seated properly in the connector when I powered the car on.

This may help you with the polarity if you are talking about LED's.

Link to my cluster job