ECM Code Issue

[franklin2]

Haven't found pin numbers yet, but have found wire colors.

Yellow is battery power coming directly from a fusible link

Darkblue is battery power leaving the relay, this goes to another fusible link and then it changes to red to feed all the 12v electrical for the fuel injection system.

Red/lightgreen comes from the ignition switch, and goes to the coil of the relay

Black/lightgreen is the ground for the coil of the relay. This wire goes to a splice and then heads for that important ground that goes to the battery negative directly.

 

[franklin2]

From what I can tell so far, the two smaller terminals, 1 and 2, are the relay coil. The larger terminals, 3 and 4 are powering the fuel injection system.

If you are putting your meter on ohms and poking around without the power connected, you will get all kinds of readings.

 

[BoomTexan]

I just found this diagram of the full engine wiring harness, will be going over my truck tomorrow and tracing back all the leads from the EEC connection. Technically from a Bronco II, but should be the same diagram. What it's looking like is that between the EEC relay and where it feeds the fuel pump, that fusible link might be blown, could be the cause of that sparking action I was getting.
The Haynes manual doesn't show that, this seems to be the official Ford diagram so I trust it a little more. Gonna go searching for that link, if it's reading continuous, I'll break apart that splitting connection and test for ground at all the individual points, if it's split, then hopefully that could be a solution.

 

[franklin2]

The above is not the official Ford diagram, it's a reproduction that Chilton's uses. It can be used, but does not get into the detail that the Ford diagram would. Best place for the Ford diagram is get one off of ebay in the EVTM book. You will noticed the above diagram shows no connectors anywhere.