Okay, been trying to finish up the wiring and I have a few questions. Centech harness is installed and I've started reworking the Mustang harness.
I've created a common ground and wired the power circuits per Ryan's website. I do not know what to do with these wires.
Centech Harness:
IGN PWR
COIL+
Choke (I guess this can be removed)
Idle Sol
Dist Mod
Mustang Harness
Manual Transmission Signal Return (I have an auto...Remove?)
Low Oil (Remove?)
12v Start for TFI
NDS PIN 30
Ground for PIN 30 (Am I over thinking this one?)
Fuel ON (this is coming from the computer. Is it the switch PWR for the fuel relay?)
Also, I only have 2 coil wires coming from the harness but my coil has 4 connections on the pigtail.
Mustang/Centech Harness EFI Questions
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dsmith01
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Viperwolf1
Re: Mustang/Centech Harness EFI Questions
I'm not real familiar with the centech labelling. Ign pwr and coil+ sound like the same thing to me. Tell me what they go to and I can figure out what the difference is. You'll need to use one of those to trigger the EFI relays.
Choke, idle solenoid and dist mod wires are not needed but might be useful in the future. Should be 12V in RUN. Either would also work to trigger the relays.
Remove the low oil wire. It works with the mustang instrument cluster not the ECM.
I would wire the pin #46/pin #30/NSS like the RJM harness with a pluggable jumper. For example, put a male connector on the pin #46 wire and female connectors on the pin #30 wire and another wire going to the "S" terminal of the starter solenoid. This would allow you to use either a manual or auto ECM by simply swapping the connector. Auto ECM connects pin #46 to "S", manual ECM connects it to pin #30.
What is fuel ON? Pin #22 in the ECM is a ground that turns on the fuel pump relay.
TFI START signal is pin #3 of TFI connector. It gets connected to "S" terminal of starter solenoid also.
Choke, idle solenoid and dist mod wires are not needed but might be useful in the future. Should be 12V in RUN. Either would also work to trigger the relays.
Remove the low oil wire. It works with the mustang instrument cluster not the ECM.
I would wire the pin #46/pin #30/NSS like the RJM harness with a pluggable jumper. For example, put a male connector on the pin #46 wire and female connectors on the pin #30 wire and another wire going to the "S" terminal of the starter solenoid. This would allow you to use either a manual or auto ECM by simply swapping the connector. Auto ECM connects pin #46 to "S", manual ECM connects it to pin #30.
What is fuel ON? Pin #22 in the ECM is a ground that turns on the fuel pump relay.
TFI START signal is pin #3 of TFI connector. It gets connected to "S" terminal of starter solenoid also.
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dsmith01
- Official CCB Member

- Posts: 215
- Joined: Wed Dec 29, 2010 2:50 pm
Re: Mustang/Centech Harness EFI Questions
Viperwolf1 wrote:I'm not real familiar with the centech labelling. Ign pwr and coil+ sound like the same thing to me. Tell me what they go to and I can figure out what the difference is. You'll need to use one of those to trigger the EFI relays.
Choke, idle solenoid and dist mod wires are not needed but might be useful in the future. Should be 12V in RUN. Either would also work to trigger the relays.
Remove the low oil wire. It works with the mustang instrument cluster not the ECM.
I would wire the pin #46/pin #30/NSS like the RJM harness with a pluggable jumper. For example, put a male connector on the pin #46 wire and female connectors on the pin #30 wire and another wire going to the "S" terminal of the starter solenoid. This would allow you to use either a manual or auto ECM by simply swapping the connector. Auto ECM connects pin #46 to "S", manual ECM connects it to pin #30.
What is fuel ON? Pin #22 in the ECM is a ground that turns on the fuel pump relay.
TFI START signal is pin #3 of TFI connector. It gets connected to "S" terminal of starter solenoid also.
Thanks Viper, you that man! I traced the Centech wires and the other end of the Coil+ wire connects to the (I) terminal on the starter relay and I think I can remove from (I) and put on (S) terminal to for the TFI start (PIN #3), is that possible or is (I) required for something else?. The Ign Pwr wire goes back to the fuse box and supplies power with the ignition in the run position. I decided to use the Ign Pwr wire to trigger the EFI relays.
The Centech harness came with a male/female terminal that allows quick removal of the choke, idle solenoid and dist mod wires. I just removed those for now. Also removed the low oil wire.
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Viperwolf1
Re: Mustang/Centech Harness EFI Questions
Ok. You can use the coil+ for TFI start. In fact you can even leave it on the "I" terminal if you want. "I" and "S" see the same voltage at the same time.