Do I need the explorer motor harness and firewall harness?

[Johnnyb]

So I thought I'd pile on all the other explorer EFI conversion questions recently and ask this one simple question:
Do I need just the explorer motor harness or do I need the firewall harness as well?

I had a couple deals fall through for a complete harness, so now I'm shopping eBay. I got an email from EFI guy, with very detailed information, but he's 3 months or more out on harness reworks. I'm pretty sure I can do it myself following his videos but I want to make sure I get started with the right parts.

Thanks,
JB

 

[904Bronco]

If you are running an Auto trans you need that from a 4R70w, with the large Grey plug. If you are running a manual trans, then you still need it, but it will be significantly paired down.
You need the Engine main harness, plugs into the ECU and has the large black plug on it. (C-115 I believe is the technical name) You need the matching plug to this from the chassis, with as much tail as you can get. You want to minimize how many splices you will have, failure points, even if you crimp, solder, and lined shrink tube them. The main engine harness will also have the matching grey plug to the grey plug on the trans harness.
Consider the Alt/AC harness, if you have any plans for that later. At minimum you have it for the Alt.
Inertia switch and long tail...
OBD under dash plug with a long tail if possible
If you run the Explorer fuel pump assembly in your aftermarket tank, then you want the matching plug from the body harness.
You can use the explorer fuse box assembly, but the connectors used in that are made of unobtanium. Garry has looked and I have looked through every wiring booth at SEMA. UTL. So more crimp/solder/shrink
Then there is the fuse box he uses from Amazon, I am sure he share the PT#. I have it but, not here on my vacation.
Finally, there is a diode in the fuse box that he uses when he rewires. I have pulled a few from the wreaking yard and even bought one new form Ford. Again that number is at home.

I think that is it.
Doug.

 

[Johnnyb]

Thanks for the detailed reply. I will continue my search, looking for a more complete harness.

I am not running auto, but I will need OBD2, alternator, etc.

-JB