So here's what I've got, looking for some informed input from anyone in the know. 05 6.0 that had a hard start issue, fixed with a HPOP to branch tube fitting replacing the STC fitting and new oil feed tubes in the HPO rail. So in doing testing, tested the FICM and voltage was a solid 48.2 with key on cold and cranking so I ruled that out as a poss. problem. After repairs I still had a hard start for a while so I tested again, also 48.2v at key on and crank, however with it running it droped to 33v. Did some reading and seemed that it should be 48v running too. What I found was after I ran the truck and got it up to full op. temp., voltage was at 48.2 running?? Checked it again today cold and same thing, 48.2v at key on and crank, 33.6v running. Watched it and tested for about 10 min while truck ran at idle, voltage slowly and steadily crept up to about 40v and if i kept it running I'm sure it would reach 48. So, sorry to be long winded, but wanted all the info for those who can process it, my question is, does this sound normal or should it be 48v across the board at all times, and if so does this sound like a candidate for the DIY re-solder fix?

 

You definitely need to deal with this issue sooner than later before you are left stranded. You are correct. FICM voltage should be 47.5 to 49.0 volts under all operating conditions. Whether you choose to replace or re-solder is entirely up to you. I've never re-soldered a FICM so I can't comment on its effectiveness.

 

Thanks for your reply m-chan, I've read alot of theories on why these fail, and one that seems appropriate to my problem says that the heat generated under the hood of these trucks and the placement of the FICM near the turbo causes the solder on the circuit boards to become brittle and break. This seems to make sense on mine with the voltage being low when cold as the joints would be at there most contracted, then as it heats up they expand increasing conductivity?? Who knows for sure, but seems logical to me. I think I'll go ahead and try the resolder, but I also just read that Ford released an option to only buy half the FICM, just the half with the bad circuit board I suppose, do you have any information about that? Price, part number? Thanks again!