Originally Posted by 64rcs

Correct. I have it hooked up the same as the turn signal that works.
I appreciate your help Richard.

Originally Posted by RB04Av

You don't necessarily have to have the resistors for that. They make flashers that are smarter and can handle it. I also have all LEDs for my exterior lighting; new housings in the rear, and replacement bulbs in the front; and a replacement flasher that works just fine without resistors. Like this one. https://www.amazon.com/Novita-LM487-.../dp/B001KS6GIG My OE flasher did the "hyper flash" thing you see the little fart-can imports doing all the time. For the same reason no doubt. I've heard of other fixes for this but have no idea whether they work or not.

The resistors aren't "in-line" electrically, although that's what it looks like from the way they hook up; they're actually in parallel with the lights. All they do is draw enough extra current to make the load look normal to the flasher that is expecting lots of light bulb current.

You DO however need resistors in the brake light circuit for the cruise to work right. I found that out the hard way. There might be some sort of tuning or something that can be done, a voltage threshold or the like on the brake light line that you could set, that would cure this. But apparently the LED bulbs don't pull the brake light line down to ground effectively enough for the cruise. It thinks the brakes are on all the time. I put ONE resistor in the brake light circuit and that made the voltage on the brake light line go low enough for the cruise to work again.

If one side of the truck works but not the other, I doubt it's a flasher problem, as such, since both sides use the same flasher. If your setup uses the OE sockets I'd suggest doing the simple thing and just turning around the way the plugs go into the bulb sockets, and see if it changes. LEDs are often polarized and require 12V to be specifically on one pin and ground on the other, and will not work if hooked up the other way.