i started my 02 ford f 350 and it ideled at 900rpm to 950rpm all morning long

 

If you tap the brake does it stop?

Is it cold where your at right now?

 

yea it is colder were i am at. If i tap the brake the rpm will not go down. some thing broke because i used to be able to tap the brake and the rpm would go down

 

Auto or Manual?

Chipped or stock?

Parking brake set?

 

no parking break set. auto . My truck is all stock. motor and trans have not been messed with. My truck has 185, 651 thousand miles also. It was 26 oF out side last night. It might have went down later in the night. Thanks for the help

 

When its very cold out it will drop for a few seconds so you can put it in gear, but it will idle high to help warm the motor.

Are your brake lights working? Almost sounds as if your brake light switch is not working.