Ok so I put leds in my 3rd brake light and lost my cruise control. So my question is what ohm resistor do i need to wire in to fix my problem?

 

Looks like 25 ohms will do it. You can buy a load resister kit from SuperBrightLEDs here: http://www.superbrightleds.com/tail-brake-turn.html

The resister kits are near the bottom of the page.

- Jack

 

why do you loose your cruise control from changing the 3rd brake lights?

 

Because the resistive load offered by the LEDs is interpreted by the system as a burned out brake light. If you lose a brake light, the cruise control does not operate. You can think of it as a "warning" that a brake light is out. IF you lose all of your brake lights, you won't be able to put the truck in gear. (Ford doesn't want you to drive with no brake lights).

- Jack