I have checked all harnesses from valve covers to ecm I was told IDM controler was on fire wall under dash under seat on floor plan?
Thanks M

Hi! mrxwesty, welcome to AMHD :)

It would help if we had a little more information.

• Year
• make
• model
• Left/right hand driver?

On a '99 Ford Powerstroke it's...
Drivers side front inner fender well, the IDM is located just rearward of the highest spot on the wheel well.

96 CC F350
Inside of the passengers fender, near to the hood spring.

What makes you think it's a blown fuse, maybe it's a no start situation?

See:
PowerStroke diagnosis

K