Question

When disconnected from PCM and coil, should the harness resistance be 0? I got the engine code P0351

Answer 1

No the resistance should not be at zero, Depending on the ohm meter you have measure with the setting on the low ohms menu, you should have some resistance

Answer 2

P0351 FORD Code - Ignition Coil 'A' Primary/Secondary Circuit
Read more: https://www.autocodes.com/p0351_ford.html