New guy... LED issues

[cmomola]

Hi all! I just wanted to introduce myself and share a few photos... I bought my square body when I was 18 and she has stayed pretty much original. First pics are when I first got her around 2007. I've recently started taking off the old and preparing it for new. One of the main things I wanted to do was change over to LED lights. Everything works until I run the truck with the headlights on, then the rear tail lights blink once and stay solid. I've already swapped the relay, grounded it, and reversed polarity... Any suggestions?

 

[Moodyalaskan]

If the front only blinks once also, the LEDs are probably not drawing enough power to heat up the blinker relay enough to let it blink more. You will need a resistor to give the blinker relay enough to heat it up and continue blinking. The system thinks you have a turn signal out, and it will not continue flashing.

 

[cmomola]

The fronts are blinking fine along with the side markers. The rear are the only issue and only when the truck is running and the headlights are turned on. If the key is turned to Aux and the headlights are on, everything blinks fine.