So, Truck let me down last week. At a cabin on top of a ridge at 3800ft. got down to the valley at 1600ft with no power brakes or steering with 14" wide tires. Fun stuff. Towed to ford and turns out it wasn't just the ICP that failed it was the harness as well. With that being said, My truck is an early early build before 1/30/03 and calls for the more expensive harness. Guy behind the counter said that it looked as if the FICM and injectors were part of the same harness is why it's more expensive. I DO NOT have a harness that incorporates the FICM and Injector Harness into the main engine harness. The main harness plugs into the FICM for logic, and a harness that comes off and goes to the injectors. They are SEPERATE HARNESSES. 3C3Z-12B637-AB is what Ford says it calls for which is $1200 and is NOT available, and 3C3Z-12B637-BA is $800 and IS available. Can anyone chime in that knows the TRUE differences on these two part numbers and if the guy knew what he was talking about? I don't mind spending the money on the proper harness. I'm not trying to cop out on the price alone. This truck is my favorite and I want it to be right. I can rebuild my old if needed but I would rather get a new one and be done with it for a while. I'll rebuild my original before I pilfer from the junkyard.

I trust you guys so if you need the VIN# PM me. I'll be checking this as often as I am able. And also thanks in advance if you can help!

 

Just for a bump I'll elaborate on the issue. I was on vacation with my wife for my anniversary. On the day we were supposed to go home i started the truck and it went dead a second later. Wouldn't run. So being at the top of this ridge I could just see a tow truck rolling down the mountain with mine on the back of it so I made it down the only way I could. Got it to the dealer and the ICP didn't fix it, so he dug a little more and found signal at the PCM and midway through the harness but not at the ICP. Also there was oil on the EBP sensor that made it's way all the way through the harness from the failed ICP. Ford didn't have the 3C3Z-12B637-AB and it's backordered until the middle of the month so I coerced my Dad into running a gooseneck from MS to NC( Four days after we were meant to return) to pick up the truck. Now it's home and I'm still in the same position because of harness availability and I am behind on my garden and everything else because of the extended stay. Anyone have any info on the harness??

Bump

 

The current number I have for it is 3C3Z-12B637-BA ("BA" instead of "AB" as you noted).

Maybe these guys can get it to you quick:
https://www.ficmrepair.com/index.cfm...rod/prd252.htm

 

I think the early harness is more of a mystery to any but the Ford Techs. You might want to send a PM to M-chan68 and see if he remembers.

Marks "B" would be an upgrade. Most of the harnesses also have Internationals designation C91, C92, C93. I'm not sure if a second-generation harness would not fit up, but you would also need the FICM harness then.

 

Not sure what they upgraded (I agree - would be good to know specifically), but 99% sure that that will fit all 03's.

 

It might be the length of some of the wires to keep from chafing or a general re-route. I remember Chris had issues with a harness change due to positioning or the wrap/lay of the harness.

 

I thought that was the engine harness and not an injector harness fit issue, but very well could be remembering wrong.

 

I didn't see his second post. Looks like the engine harness is the component of the harness that he needs. I mistakenly read post #1 as he needed the injector wiring.

EDIT - I also had 3C3Z-12B637-BA (mistakenly) in my spreadsheet as the injector harness portion. Looks like I was mistaken on that also. It IS the engine harness component! (as an fyi - 3C3Z-9D930-AA is the separate injector harness). So looks like the BA should work for him since he has separate harnesses (if I finally read it all right)

 

I was getting confused here too. He just needs an engine harness, not the first generation one harness for everything.

 

That is correct. Only Engine and not the injection harness, it's less than three years old. And thanks to both of you.

 

Sorry for the confusion on my end. This post identified an error in my parts list - so thanks to you!

 

Glad to be of assistance! lol PM'd with VIN

 

I sent a PM to him, thank you.

 

m-chan68 is the expert on this forum for Tech advice and part numbers. Hopefully my contact will get back with me in reasonably short order. If not, PM'ing m-chan68 as Jack suggested would be the best bet (or perhaps he will see this and have time to answer/look).

 

I don't know what I would do without you guys.