Change engine harness with engine swap, need a new harness?

Bought an unfinished 03 GT project with an unfinished engine swap. The motor is supposed to be from a 98. There are engine wire harness connectors with no place to go or the length seems way too short.
I think the engine wiring harness is the one that came with the replacement engine.

Am I right thinking I need a 99-04 engine wiring harness? If so I'm looking for a harness

RichK
AKA lowtek

Here are some pictures of what I'm trying to solve.
I'm holding one part of the harness with 2 connectors and no apparent place to connect. In some engine pictures I've seen this end wrapped around the front of the valve cover and running back above the exhaust manifold. I don't have anything in that area to connect to. Hard to see but there is a connector along the harness between the first two plugs that has an extension cable plugged into it. The extension goes nowhere and has a different connector at the other end.

The other picture shows 2 greenish plugs that are near each other along the top of the firewall. They're both the same gender and nothing to plug them into. I wonder if they're meant to plug together.

Not shown is the speed sensor cable which is too short and on the wrong side of the trans. Trans is a 3650, original equipment.

When I got this car home it was electrically dead but I hunted down 2 unconnected grounds based on pictures I saw online. The cabin now has power and the engine now cranks using a key. Not ready to fire it yet.

Mcmahst said:

If you’re up to it and think you can make the merger, first thing you need are the two wiring diagrams for the car itself and then the engine; make sure you’ve verified the engine/ECU before you obtain that diagram. From there, you can I’d each of the car harnesses that you’ll need to connect to the older engine harness.

If electrical stuff isn’t your thing, you’ve got to decide if you want to learn, pay someone else (yikes), get a ‘03 engine/harness, or sell and get a new project. I choose option 1; I did something like this last 2 years on my 73, and it was a great learning experience. But get good diagrams/schematics, the ones that I’d the connectors. Ford made wiring diagnostic manuals, I had one for my donor car, so I suspect they still make them. Good luck.

Click to expand...

I'm thinking about getting a harness.

Figured it out. O2 sensors point to the sky because the harness is flipped at the firewall. Part of the harness should be 6-8 inches lower and run across the top of the bellhousing attached to a harness retainer.

Have to disconnect everything at the back of engine (hoses etc) and untwist it. Can't snake it under all the connections