LED tail light swap not working properly

Just swapped the old rear tail light assemblies for new C-bar LED tail lights (and 3rd brake/cargo light) as part of my custom restoration. After installation, my rear blinkers started hyper flashing, brake lights didn’t work (they “strobed” when I pressed the brakes) and the “lamp out” message appeared on the dash. Running lights work fine as does the 3rd light.

After some research I installed 8ohm/50w resistors grounded to the body and connected to the blinker wire on each rear tail light. I tested everything with the key on “acc” and the problem appeared to be solved. That is until I cranked the truck up.

With the truck running, as soon as I press the brake, the “lamp out” lights up, brakes strobe when brake is applied, and rear blinkers don’t work. Weird thing is, the front (standard bulb) blinkers work with their normal cadence. Also, the 3rd light works properly.

I’ve read that this generation of truck, particularly 02-05, is very persnickety when it comes to electrical changes.

I’m at a loss as to what to try next. I love the look of these tail lights but need them to work properly.

Any suggestions?