74 duster electrical problems

The 70 amp breaker is off of the starter relay which power everything. I have everything fused but the fuses in the panel aren't blowing.
I did check the voltage and it was 12.56 while running. My cooling fan was on and draws 19 amps so I assumed that was pulling the voltage down.
How do you check an ecu to see if it is toast and does anyone know what the resistance on the coil should be on the primiary and secondary. How much resistance should be on the distributor?


Thanks for the input.