I bought new led sequential lights for my 73 nova. I changed every light to led and the flashers (4 ways and turn). Everything works fine with key on but not so much when the engine is running. They flash fast and blink when they shouldn't be. Can figure it out? Don't know if it's the actual led tail lights or something else. Any help would be great thanks

 

You need to put resistors or replace your turn signals flasher module when you changed to LED bulbs to fix the hyper flash issue, I would contact Xtralights online to see if they have the resistors/flasher unit for your car.

 

I also have a 73 nova and put sequential LEDs. Flashers also, your problem in electronic noise. Check your alternator. I did this and everything was fine. Then to recall I also installed a msd hei billet distributor at the same time. Called msd and they admitted that it was the abundance of power for the coil and if my wires were anywhere by the distributor that would be a problem. Hope this helps you out