Explorer 5.0L wiring harness swap in complete? Is EFI Guy Garry still around?

[skrit]

So I'm planning to use the as MUCH of the original Explorer harness as possible (EGR, O2 Sensors, PATS, EVAP, etc.). I know @EFI Guy is around every so often and is the guru. I'm trying to do a complete electrical swap without reprogramming the PCM.

I have this mess and a few good wiring diagrams but I'm having trouble with identifying the main connectors after the firewall so that I can keep following the diagrams. The engine side wiring is complete with everything plugged in as it was OEM. After the firewall, there are 3 big gray, brown and black connectors that are all together and a giant gray one that is downstream (beside where I have something labeled brake pressure).

I wish there was an illustrated picture of the connectors showing the "Cxxx" numbers. Any links to connector ID diagrams or better diagrams than this is much appreciated:

Oh and ignore the flexible exhaust pipe - it is just for mock up purposes for now.

 

[bigmuddy]

He's still around.

 

[EFI Guy]

Now that I have retired from the mechanic life I no longer have access to those extra diagrams. I never saw the point in saving them because I would bet that less than 10% of the wires going through those 3 connectors are needed to make it run. There are so many extra circuits going through there that you don't need that you would probably spend more time sorting them out than doing the rework as I show you. If you wanted to keep the firewall pass through plugs you can, but you could just repin all of your needed circuits down into one of those connectors and still have empty cavities.

In your situation, I would just follow my #2 video. There is no need for you to rework the engine or transmission harness. The Evap wires are present in your C115, you will need to find the vent valve, purge valve, and fuel tank pressure sensor and wire them into the matching colors in the C115.

For PATS you'll need the module and the transceiver. Patch it into the matching wires on the OBD2 port. Hopefully, you have at least 2 programmed keys?

Also, the diagrams you are using say 99. The green o2 connectors tell me you are working with a 96-98. If it does have PATS then you are working with a 98. I don't know what differences there would be for those firewall plugs, but if you're going that route you will want the correct diagrams.

 

[skrit]

Now that I have retired from the mechanic life I no longer have access to those extra diagrams. I never saw the point in saving them because I would bet that less than 10% of the wires going through those 3 connectors are needed to make it run. There are so many extra circuits going through there that you don't need that you would probably spend more time sorting them out than doing the rework as I show you. If you wanted to keep the firewall pass through plugs you can, but you could just repin all of your needed circuits down into one of those connectors and still have empty cavities.

In your situation, I would just follow my #2 video. There is no need for you to rework the engine or transmission harness. The Evap wires are present in your C115, you will need to find the vent valve, purge valve, and fuel tank pressure sensor and wire them into the matching colors in the C115.

For PATS you'll need the module and the transceiver. Patch it into the matching wires on the OBD2 port. Hopefully, you have at least 2 programmed keys?

Also, the diagrams you are using say 99. The green o2 connectors tell me you are working with a 96-98. If it does have PATS then you are working with a 98. I don't know what differences there would be for those firewall plugs, but if you're going that route you will want the correct diagrams

@EFI Guy

Garry,

Thanks so much for your reply and hope you're enjoying retirement. As I watched through your videos earlier today - I realized there is way too much wiring to trace down and not even use - just like you said. I'm going to start whittling it down. At first I thought I'd just throw the whole harness in and not connect un-important things that would have no impact on the PCM but now I've rethought that seeing the sheer amount of wires. I just want a modern computer controlled drivetrain with ODBII that will fire right up and not smell like gas fumes.

Other than rear fuel tank pump, pressure sensor and related evap canister wiring, the PATS wiring, 4R70w harness, 02 sensors...there really isn't much else from the firewall back I really need do I?

The diagram I have is 1999 because it was the only one I could find to download for free. I have a 1998ish used for donor parts (sold as a 1999 but one of the later 1998's). I have one key, the PATS, the ignition cylinder and the receiver ring for the key and the entire steering column. Hopefully 1 key is enough.

I did end up finding out those 3 big firewall plug ID's which are C146, C147 and C148 so my understanding of this wiring harness is increasing by the hour.

I'm starting on a more simplified diagram that is connector centric to help me visualize it all.

 

[EFI Guy]

Don't forget the inertia switch and pigtail.

With 2 programmed keys, you are able to program more yourself without and fancy scantools. When you only have one you'll need a higher end scantool to add a key.
Just remember PATS will only stop the amateur guy attempting to hotwire it. Anyone professional would bring a PCM without PATS or a rollback. Losing your only programmed key will have you calling the rollback yourself.

If this is a 98 harness then it will not have a VSS connector down at the transmission, you will need to add it in. C115 #33 goes down to the transmission but isn't used. Use it for your VSS+ and the black wire next to it on the DTRS as your VSS- and you can avoid opening the engine harness to add VSS in.