A9P ECM Pin 30 Question

[markinms]

Finalizing wiring for my 5.0L. 5.0L is from a 1990 Town Car. I've integrated wiring harnesses from the donor vehicle and my 87 BII. I used factory wiring charts to complete.

I have also reviewed the Ford Motor Sport Multiport EFI Engine Management Harness instructions. It makes NO reference to the type/model of ECM being used.

I also reviewed the Painless Wiring! Wire Harness Installation Instructions for Installing the Ford 5.0L 1986-93 Wiring Harness. Their instructions DO reference using the A9P ECM with an automatic transmission.

Painless Wiring! has a diagram showing Red/Blue wire from ECM Pin 30 going straight to the starter solenoid/relay. They claim failing to do so can damage the ECM. This is different from my Town Car wiring.

A lot of background to get to this question:

If you have a 5.0L with an automatic transmission and are using a A9P ECM, how did you wire pin 30?

Thanks!

Mark

 

[markinms]

I stumbled on this post in TRS Archives. I copied the text to use as a reference but unfortunately failed to note who the original poster was. If this was your post, thanks for the info.

From original poster:

"An Automatic fox body Mustang sends 12v to pin30 during a start. This is accomplished is the O2 harness (a loop right in the connector to the engine harness). There is an extra circuit in the engine harness that connects to the starter relay (fender mounted) on an automatic car. This is absolutely not need in a Ranger swap, and is the only auto/manual difference that applies to us.
In a manual Mustang, the loop in the O2 harness connector connects pin30 of the ECU to pin46 (the signal return, basically a sensor ground shared by all sensors)

In lieu of searching for the "correct" O2 harness for us swappers, you can simply splice the appropriate circuits together (pin 30 to starter relay, or pin30 to pin46) on the engine harness side of the O2 connector. This can be done right at the O2 harness connector, or as I did on my latest harness, somewhere near the firewall.

Hope this helps someone simplify this stuff."