No power to ficm??
 

Truck is a 2004 f250 6.0
Mods 4in turbo back, new motorcraft filters, fresh oil change.
So I installed a new ficm in my truck a week ago
Truck ran good for 3 days started fine. So the other day I went to the store got the truck up to running temp. Then shut it down for 20 minutes or so came back out and it won't start. Thought it might be a Hpop leak but icp was over 800 when I tryed to start it. Also I have no power to my new ficm. I checked the plugs on the ficm they are all the way in. And batteries are good.
So not sure what it could be right now ficm shows 8 volts.

Could I have a ficm harness issue? Like chafing wire? And if so how would I replace it with a new harness?

Thanks

Check all of your fuses, also there is a FICM relay too

How do I check a relay?