No crank no start?

Hello Joe. Thanks for reaching out to me.

Damaged and melted was the black (ground) wire coming out of the ECM. I replaced it with a new wire (same gauge) and grounded it in back of engine... Running to the same pin as the fried wire.
When I tried starting it from the ignition, there’s power but no crank or click. When I bypass the ignition through the fuse box crank relay connections, I get a click. It did turn over doing that earlier, but now it’s back to just clicking again once, with each repeated attempt.

There are other electrical components working, like the lights, exterior and interior, radio, etc. Previous to this challenge, I was experiencing the engine overheating (at least the car’s computer was alerting me of that fact). Previous to the overheating, the vehicle stopped blowing hot air (started doing that a couple years ago or so). That got worse and worse until the overheating started taking over this past year. I bypassed the heater core, and the vehicle stopped overheating. I was slowly losing coolant before, as it seems it was not getting past the heater core or something, filling my vehicle up with coolant smell and getting that film on the interior windows? That made the coolant get low, I do believe, but now it’s staying pretty level, though I haven’t had the vehicle running in almost a month.
-Ron