So, #1 injector / cylinder is not firing. We already replaced the UNCH and injector only to later discover that the problem was electrical. Ohm'ed the IDM and it passed those tests. Ohm'ed the 42 pin connector at the driver side head and it looks like there is an issue with the female side of the harness that sits in the valley.

Where does one get one of these harnesses?
Any idea on cost?
Has anyone had success with used / known good harnesses?
I wouldn't mind saving a couple of bucks if someone has a good used one.

Thanks.

 

Well I don't know if they make a repair harness for that but if you are only having a problem with on of the pins I would think you could take the harness plug apart and just replace the one pin. You might be able to find a donor plug pin at a junk yard. Now since you say it is the female side I am wondering if a replacement plug for the outside of valve cover has the same size pin because if so you could take one of them apart and use it to repair your 42 pin plug.

Now this idea is less than ideal but I have had to do this before in the past. That is too just bypass the 42 pin plug with just the wires that have bad pins. It isn't pretty but will get the job done. Besides how many times do you actually disconnect that plug anyways. Sorry just spit balling ideas.

Also it might just be a bad wire so I would cut the harness open and look for a broken wire first.

Hopefully someone who has had this issue and found a real answer. Good luck

 

Interesting idea but I don't really have the time to play around trying to bypass it or actually find the bad wire. It would be quicker for me to just replace.

 

Might call dealership just to get an idea of price & availability

 

Take a deep breath and call the dealer.

I suspect they can get you one.

Pop

 

After you call the dealer and then after your jaw comes back up off the floor, think about how little time it would actually take to get it back up and running.

Look at the pin out for the 42 pin connector and cut the corresponding wire 4" past the connector. Do the same at the valve cover plug. Then just splice in a wire between the two.

You don't have to route it pretty, you don't have to look for a problem with the other wire, just bypass the wire as a quick test and then decide what you want to do.

But first, make sure it's not a bad pass thru pin in the valve cover gasket. No reason to cut the wires if it's a burnt or loose pin.

 

I just replaced my harness from the 42-pin back over the engine. Final price at the dealer was $750 + tax, retail is around $1100, but I found a better price on the internet from another dealer after searching with the part number, but did not have time to order it from them - that cost me $300+. My part number was wrapped around the harness just behind the alternator. The tag was double wrapped so if the PN is hard to read you can carefully unwrap the tag and see the full PN. My OEM was made in Brazil/Navistar but the OEM from the dealer was made in Mexico. A new engine harness is very stiff and makes routing difficult. I had some serious injector wiring issues with brittle insulation on the passenger side - hey, my truck is twelve years old and driven a LOT. I did the engine harness while I did my planned UVCH on both sides with new GP's so it only cost me a day or two extra.

Good luck pilgrim,

 

Good grief that is expensive.

I'm a wiring idiot so a little scared about hacking things up and making a bigger problem than I already have. However, I think I can probably muster enough skill to run a new wire from behind the male side of the 42 pin connector to the UVCH bypassing the huge snake of wires in between.

Do any of you guys know where I'd connect the wire to at the passenger side head? Is there a specific wire for injector #1? I can figure out which wire it is at the 42 pin connector based on this pic but not sure which wire is the correct one at the other end...

https://www.ford-trucks.com/forums/1...or-wiring.html

Also, is the #1 injector on the same pin on all years?

Thanks fellas.

 

Wiring is the same for all years. The link you posted shows which pin in the 42 pin connector is for #1. On the connector at the valve cover on the passenger side, #1 cylinder injector wire will be the 3rd wire back counting from the front to rear.

 

if you need a couple pins for the connector i may have some. I grabbed a bunch from a junk yard. The 42 pin connectors come apart easily.

 

Thanks Chris

Thanks and Sorry Dan but not sure I understand.

 

 

Just saying, encase or if you need to pull a wire or two and need pins extra pins for that 41 pin connector. Or if you have a damaged pin.

 

AGM-SM
The injector wiring in mine was wrapped with foil about six or eight inches from the vc and the 42 pin connector. This may be for the radio noise - not sure or it could be for the interference of the 115 vdc going through those wires or possibly from the other wiring very close to these injector wires.

 

Update

So the above suggestion sounds simple enough right. I attempted it today using Tugly's picture as a schematic.

I tapped the wire to the UVCH connector like so:


Then I spliced into the wire on the male side of the 42 pin connector that corresponded the #1 injector - so the 1st wire at the bottom left of the male connector from the perspective of staring at the pin side. Bottom rear when looking at the connector installed on the truck.

Started the truck. Huge clouds of smoke started pouring out the exhaust. Revved it a couple of times and could hear some odd electric click under the engine bay. Truck was NOT happy... Shut it off and scratched my head a while.

I decided to give up so I cut the wire and started the truck. No smoke. Smoothest idle the truck has ever had. Revved it up. Revved nice and smooth. The SES light even turned off. WTF...

Somehow the problem went away. Not exactly sure why but the truck is running normally. Drove it right over to the smog station and got the truck smogged. I can finally register the truck.