Aftermarket wiring harness to RJM harness

[pgrem]

I'm in the middle of installing an American Auto Wire harness in my '76. Looking for advice on how to hook it to my RJM EFI harness.
The RJM engine harness already runs to the alternator and starter solenoid. I assume I don't need to connect the AAW harness to the same components? The RJM ties into the original Bronco harness through a three wire red plug at the firewall in the engine compartment. Seems like it would be best to connect the AAW harness through that corresponding plug on the RJM?
Anyone have experience connecting the two harnesses together?

 

[Viperwolf1]

The AAW harness will need to connect to the EFI harness just like the Bronco harness did. It will also have at least one wire going to the starter solenoid.

 

[66horse]

What viperwolf said.

Three wires are oil press, temp and hot (coil). Those are the junction points of the two harnesses. And there will be a wire from both the rjm harness and the bronco harness connected to the starter solenoid.

What alternator are you running? Iirc that matter re wiring from rjm harness or bronco harness.

Cheers,
Steve

 

[ransil]

Start & Run wires are the important ones that connect to the RJM harness. should be in the AAW harness somewhere.

 

[pgrem]

Not sure what alternator I'm running now. I did not install this engine. I'll definitely upgrade to the one wire alternator in this process.
Spoke to AAW today. They helped me identify a pink wire in the harness that is un-fused and hot in crank and run.
So far this is what I understand;
1. Power comes into the AAW harness from the positive side of the solenoid.
2. Connect the AAW pink wire that is hot in crank and run to the RJM harness at the same interface as the original Bronco harness.
3. The RJM harness will maintain its power supply from the solenoid.

Need to confirm the following:
1. Is the RJM harness supplying power to the coil? I assume it is and will not need to change.
2. Planning to look at the wiring diagram for the RJM harness tonight to determine if I can slice the red plug from the original bronco harness into the AAW harness.

I am a serious wiring and electrical novice. Hoping this will help others in the future.
I would appreciate any suggestions and confirmation or correction of my assumptions above.

Paul

 

[DirtDonk]

All the ignition coil duties are handled by the ECU through the RJM harness. So you're good there.

If you're talking about the Violet/Purple wire in the RJM harness, which most might connect to the "S" post on the starter relay/solenoid, I'm not sure you can use the Pink wire you're talking about, because I'm pretty sure that the Violet (Purple) wire to the RJM harness wants to see ONLY power in START and not power in RUN too.
If you're just talking about the RJM wire to turn things on (Red maybe?) then that would be ok, but it's better to connect it to where it's expecting, which would be the old red connector area of the firewall. With the new AAW harness, not sure if that's where the wires exit or not.

And speaking of which, I'm not sure what you mean by using the old Red plug, since your new AAW harness doesn't use it. Correct?
But those wires are exactly what you would use for RJM. Power on with the key, water temp, and oil pressure. As someone mentioned previously.

Paul