Right after the engine starts, I sometimes get a very low whining-buzzing sound coming from the driver's side interior under the steering wheel, close to where the IEEE connector is for the computer hookup. It is intermittent, and stops a minute or two after the engine is started. Any ideas ?

seatbelt warning........

Down in the bottom of the control unit/fuse box (under the hood) there is a small fan that draws in interior air to try to keep the control modules at an even temp when the truck is running. Sounds possibly like it's that thing, I've replaced a few of them.

Gilly