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Discussion Starter · #1 ·
After having the truck apart to replace a cracked oil filter base, re assembled everything, plugged everything back in. Truck doesn't start, no injector clatter. If i ground the FICM relay however as shown in the attachment it fires right up. Replaced relay and same issue. Any thoughts?
Circuit component Electrical wiring Electronic component Electronic engineering Motor vehicle
 

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After having the truck apart to replace a cracked oil filter base, re assembled everything, plugged everything back in. Truck doesn't start, no injector clatter. If i ground the FICM relay however as shown in the attachment it fires right up. Replaced relay and same issue. Any thoughts? View attachment 778571
Double check the first plug on the ficm (farthest towards the front of the truck) , make 100% sure it's fully seated.
Could be a bent pin also.

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Discussion Starter · #3 ·
Double check the first plug on the ficm (farthest towards the front of the truck) , make 100% sure it's fully seated.
Could be a bent pin also.

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I checked that, checked for bent pins as well. It all looks ok. Wiggled the harness while monitoring FICM voltage on a scan tool and nothing.
 

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Check Fuse 18 (10A) in the same junction box. I'll bet you a beer it's blown.

-jokester
 

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Discussion Starter · #5 ·
Check Fuse 18 (10A) in the same junction box. I'll bet you a beer it's blown.

-jokester
All fuses are good. It's just the ground to relay 304 that isn't being supplied.
 

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All fuses are good. It's just the ground to relay 304 that isn't being supplied.
Modern day vehicles control almost every circuit through the grounds, such as when you roll a window up, the switch grounds the motor, the positive power is always on.
So the ground not being active could be coming from somewhere else, like the pcm.

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Discussion Starter · #7 ·
Would it be ok to supply the ground directly to the relay with a new wire?
 

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I seem to remember a groundint strap on the FICM harness that secures on the drivers side, somewhere towards the windshield that is easy to forget to hook up.

In my signature blocky, there’s a schematic in the “good Reading“ doc that shows the FICM relay, but only the positive leads. THat shows a 12 way connector. Looking at the linked document, I’m not really sure what you mean by grounding the relay, or which pin exactly, but appears if you do that, the relay would be on all the time.

My guess is trace back the key power wire and that is open.

If I were troubleshooting, I’d prefer a better wiring diagram than above. The Ford Wiring diagrams, expensive and I can’t find them online for free, tell you exactly which color the wire is and which connector and pin or post these wires go to. Much more info than th diagram linked above that has a line from the relay through a multi pinned connector that ends up at the FICM Plug X3 pin 7.
 

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I seem to remember a groundint strap on the FICM harness that secures on the drivers side, somewhere towards the windshield that is easy to forget to hook up.

In my signature blocky, there’s a schematic in the “good Reading“ doc that shows the FICM relay, but only the positive leads. THat shows a 12 way connector. Looking at the linked document, I’m not really sure what you mean by grounding the relay, or which pin exactly, but appears if you do that, the relay would be on all the time.

My guess is trace back the key power wire and that is open.

If I were troubleshooting, I’d prefer a better wiring diagram than above. The Ford Wiring diagrams, expensive and I can’t find them online for free, tell you exactly which color the wire is and which connector and pin or post these wires go to. Much more info than th diagram linked above that has a line from the relay through a multi pinned connector that ends up at the FICM Plug X3 pin 7.
There is a ground from the injector harness that runs off by the IPR on the drivers side if that's what you're talking about.
 

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Try a "known good" FICM. The FICM itself provides the ground to that relay.
 
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