I hadn't drove my 350 over the winter much - last fall the cruise starting going out. It would work fine, but cut out sometimes. At first it seemed to do it when it went uphill but became more frequent and seemingly random. After sitting most of winter I started driving it recent. Now it doesnt work at all until the trucks been going for a while... it never works first thing. I have a 40 mile drive into work and usually in the last 10 miles it finally works. In the evening on the drive home it takes a lot less time to start working usually. Almost seems temperature related like it has to warm up.

Seing how I drive almost entirely highway this is a pain. Any clues? It doesnt seem to have anything to do with the brake or clutch pedals, at least they operate normally and if I shake em around it doesnt seem to effect it either way.

The cruise stays 'on' but looses the setting (as if I tapped the brake pedal). For example if it cuts out on me while driving down the highway, I can tap the resume button and it often picks it back up where it was. I havent physically traced the wires or tested the pedal switches, I dont have a schematic to know what wires and contacts are what. Any ideas?

 

check the brake pressure switch on the master cylinder. It may need replaced.