Yes I've searched. I've unplugged all the things that have been suggested as possibly being wrong. After unplugging the 2 switches on the master cylinder, the parking brake switch, and the switch on the brake pedal, and leaving them all unplugged, the brake light on the dash is still lit and preventing the cruise control from working. What else is there that could be triggering the light to be on.

 

Is it a diesel? If it is and you have a regular vacuum type brake booster, they usually have a low vacuum switch mounted under the hood somewhere that will turn the brake light on. If you have a regular vacuum type brake booster with a diesel, you have a vacuum pump somewhere. There is usually a diaphragm switch that monitors that system. Al least that is they way it is on my 1989 f250.

 

Thanks. It is a diesel. I'll check for those.