'01 Cruise control problem

The cruise control on my '01 3.0L vulcan engine is acting up. The "cruise" light on the dash comes on but normally the cruise will not set. Oddly, the only times in the past month that is has worked it has been raining. It doesn't always work in the rain but it must be raining to work. Even then, the cruise can be set at 55 MPH and will stop working w/o warning or input from me. Any ideas?

Nothing brilliant, just tried and true. Pour over it from top to bottom, front to back and side to side to be sure all connectors are clean and well connected, wires are not chafed, frayed or loose inside and out. From there, I suggest :banghead: :banghead: :banghead:, as it only gets harder and more expensive from there. :shakehead: probably including a visit to the dealer :runaround: Hopefully, Rod or someone else here can offer more specific knowledge and info than that.

Not really. The data point that it only works when raining is excellent information, thank you for providing that detail. That would certainly indicate a corroded or loose connection. The problem will be locating the connection. Start at the cruise control servo, disconnect and inspect for green fuzzy corrosion. Inspect other connections in that area or in the wiring harness that the cruise servo interfaces with. Also inspect the ground connections in the engine compartment.

Have you noticed any other accessories that behave differently during rainy days?

-Rod

Thanks for the help....the cruise control seems to be the only thing that acts squirrely in the rain. I guess I'll be spending some time acquainting myself with the electrical system under the hood this weekend.
--BJ

Look at the cruise control shut off switch. Ford has recalls on a lot of vehicles and maybe your switch is starting to fail.