I have a 1997 7.3 and I can't find a straight answer. I want to simplify the factory harness "cut out unnecessary wires" to run my motor. I've seen a you tube video of one running on a stand with minimum wires. So what wires do I need and what wires can I get rid of ? Thanks

 

I think on that motor it had the idm and or the pcm mounted on the motor. I'm not sure if that would have been an international thing or a Mercury thing but I do know that Mercury also did a marine version which are as simple to run as hooking up a few wires. There is still as many wires though, just not as long. These are a very electronic motor.

 

I just want to use the engine harness only and get rid of the interior harness I'm just not to sure what I need

 

Mmmm. I can't help you with that.

 

Alright well thank you for your input

 

Tell us what you are trying to do with the engine and that will help us a bit more.

 

I have a 56 Coe cab and frame I want to use I can fab all the mounts just the electrical part isent one of my strong areas, I basically want to have one main power ground and start switch without the big fire wall connections

 

Search for Mark Fugazzotto on YouTube. He's done something very similar and is very knowledgable about the harnesses on this truck. I believe he's actually made a couple for several people.



I'd send him a PM or track him down on PSN. He's a great guy and has always helped me when ever I had a question.




As for having just one power wire and a start switch... These things aren't like a cummins. You'll HAVE to have at least a PCM and IDM.


The 7.3L is almost if not completely electronic.

 

What transmission will be behind this engine?

Do you have a 1997 EVTM?

 

If I recall correctly:
- You need 9 wires for the injectors, plus 3 or 4 from the IDM to the PCM.
- You need 2 wires for the CPS.
- You need 2 wires for the IPR.
- You need 2 wires for the EOT sensor.
- You need 3 wires for the ICP sensor.
- Plus some hots and grounds for the IDM and PCM.
This is a minimum to make the engine run.

- Plus datalink wires, tach signal, and maybe a couple I am forgetting that would be nice to have but not required.

 

You have to keep the battery light wires to the cluster. Without them the system will not charge

 

That could be, I used a 1 wire alternator so that didn't matter.

 

- Pedal position sensor and idle switch
- MAP and BARO
- Glow plug wiring
- Speed signal if automatic, or if OP wants cruise control.

OP might be using another charging system.

 

Don't need BARO for anything useful, but need MAP for sure.
Don't need GP's, I doubt he'd be driving a '56 COE in the cold.
Speed signal if you want a total nightmare to get the stock trans to work correctly. Otherwise go with a mildly built C6.

 

BARO is also an input to the injection timing. IIRC, it compares BARO with MAP to get actual boost pressure. It *MIGHT* default to sea level atmospheric when absent, which would only throw it off at high elevations.
90F is COLD to a PSD (actually, to just about any diesel). It gets into the 90s-F here, and both our PSD and my IDI still need glow plugs when they've been parked. And when _doesn't_ it get "cold"? In the midwest, it goes down close to 40F 12 months of the year.
Or just put a manual behind it. But agreed, an E4Oh$#!+ would not be much fun to put in this project.