i bought some led tail light bulbs for my 66 coronet and only one side works. put the old bulbs back in and they work. Somebody said something about getting a no load flasher? anyone run into this problem? What flasher did you use?

If you are having an issue with the blinkers you will need a Electric flasher relay. Any parts store should have them.

Some LEDS are polarity specific so be sure the bulbs are in good.

Switch sides with the bulb to test and if you can turn them 180 degrees.

Brake bulbs itself shouldn't need anything special. Where you need an electronic flasher is for the blinkers/turnsignals. I put LED in my car and they wouldn't blink, just came on and stayed on. Put an electronic flasher in the hazard and turn signal with the pigtail ground and work fine now. Some are polarity sensitive and may need turned 180 degrees like the blade style in the dash. Twist and turn style can't be rotated sometimes due to offset side pegs (not the technical name, but not sure what else to call them). I got all mine from superbrightleds.com and never had to turn one around to get it to work.