LLY: Bad FICM or shorted Wire

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Mar 1, 2013
1,774
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Des Moines, Iowa
I had a friend call me last night and said his truck just died driving down the road, it cranks but will not start. So I got him back to shop and start figure it out. It had been throwing U0105, so I started digging. Found that the #1 stud 40a fuse was blow as well as the *1 EDU 25a fuse was blown. Replaced the 40 and the 25 and it keeps blowing the 25s. Next I start looking in all the usual rub spots, haven't found anything. If the FICM isn't plugged in it doesn't blow but I don't know if this means that the FICM is Bad or just without it there is no current. Any help?
 

02greysixer

Active member
Jun 4, 2011
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North Central FL
I'd check to see if you have a short to ground on your power wires or a short to power on your grounds. If not I say ficm. Could always borrow one from another truck to fully confirm. I remember an lb7 with very similar issues and it was the ficm.

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Mar 1, 2013
1,774
34
48
Des Moines, Iowa
Ya, my power to ground pins on the FICM are Ohming lower than it should for a 25amp fuse. Also it's shorted out to the case. How hard are these thinks to fix or repair? I can't find a replacement for under 400$.