2003 Sierra - Cruise Control Issue

[New Yooper]

The cruise control on my 2003 Sierra stopped working, I thought it might be in the switch, so after switching out the turn signal,wiper, flasher, dimmer, cruise control lever module, it still doesn't work. Any other ideas on what might be causing the cruise not to work???? Any suggestions would be appreciated!

 

[Beaudoque]

Did you just replace all your lights with LEDs. Changing ALL exterior light to LED will cause the cruise to fail. It senses not enough resistance in the lighting circuitry and will not allow cruise to work due to "lighting safety". I changed all my lights to LED and it worked fine until I later changed the high brake light on the cab to LED. Bingo, the cruise failed. There is a work around by putting a resistor in line that will fool the computer and the cruise will work again, but I just changed the 3rd brake light back to incandescent and my cruise worked again. Without a resistor or any incandescent bulb in the brake circuitry the computer senses that the brakes are ON all the time and will not allow the cruise to engage.