Ford EFI wiring harnesses

[the912guy]

Just curious if anyone knows if the aftermarket wiring harnesses that are made for the EFI 5.0 engines will work (with a little modification, maybe) on the SHO V6.

They both use the EEC-IV ECU, and nearly all the sensors are the same between the engines (except for maybe the DIS ignition).

I can't decide if finding and using a 14-yr old original '89 SHO harness is better, or trying one of the new $250 aftermarket 5.0 harnesses to swap my '89 SHO V6 into my '66 Porsche 912.

 

[rangerj]

912guy,

You're going to put a Yamaha V-6 in a 912 Porche?

I like the way you think! Can you get a wiring diagram of the 5.0 aftermarket harness? I think you need to compare the harnesses wire for wire in order to make a decision on whether it will work, or not.

As Tim Allen would say, "more power, rewire it"!rangerj thumbs_u

 

[the912guy]

Yeah, I've been restoring/rebuilding this 912 for years, it had a VW 1600 in it when I rescued it from the salvage yard crusher. I orignally planned to build a 2500cc VW stroker motor, but ****, I can swap in an SHO V6 and get more horsepower, torque, and EFI for about the same money (or less!).

I've already picked up a complete '89 motor, but the wiring harness back to the ECU has been completely cut in a few places. I can fix it, but it's a LOT of work - either replacing it with another complete harness or using one of the aftermarket harnesses sounds like a better deal to me. I'm pretty familiar with the EEC-IV, I autocrossed my daily driver '88 5.0 Mustang for 11 years. The ECU's are really pretty much all the same, it's the programming that's different. I know the 5.0's harness is going to require some mods to work on a SHO 3.0, but the sensors and the harness connectors shouldn't be that different (if at all.) I'm just wondering which is more work - repairing the cut harness that came with the SHO motor, or modifying a NEW 5.0 harness to run the SHO motor.

I've ordered the Ford Fuel Injection ('87-'93) manual from Amazon, but it's taking freakin' FOREVER to get here.

Kennedy Engineering actually makes an adapter plate to mate the SHO block to a Porsche 901 transaxle, and several clutch options. Plenty of room in the 912's engine bay.

I'm hoping to combine the best of German engineering, Japanese technology, and American horsepower.

 

[rangerj]

912 guy,

Repairing the cut harness is asking for glitches.
Most, if not all, of the sensors are sensitive to resistance and slight voltage variations. Splices add resistance and can cause slight voltage variances.

Salvage all the connectors and any of the 89 harness that is complete. I would still trace out each and every wire of the two harnesses and determine the exact differences.

I love it! A Japanese engine, a German body, USA electronics, a real coalition vehicle. It would be very appropriate if the floor mats were French!
boink rangerj thumbs_u

 

[Off Road SHO]

rangerj


I love it! A Japanese engine, a German body, USA electronics, a real coalition vehicle. It would be very appropriate if the floor mats were French!
boink rangerj thumbs_u [/QB]

The French do not want to get involved in this project either.

Good luck on your project. I'm doing a similar project with a 3.2 and a Mendeola 4 speed in a sand car (see signature link). I'm just starting to wire it up now and feel your pain. Maybe someone on the Forum has an old MTX they're parting out and could donate the engine and engine bay wiring harness to you.

Tom

 

[luigisho]

How about searching the internet for a late model SHO wiring harness from a salvage yard? Just be sure to communicate that it needs to be all in good order. There are salvage search engines to check many yards at once.

For the 5.0 harness it seems like all the wires and pins would have to match up. You would need a harness-pin schematic for each system to cross ref. to be sure. Or you could go the expensive route and get an aftermarket engine mgmt. system.