I'm sorry if this tread was already discussed but I couldn't find any answers for it.
I have a 2WD Sierra with MSD chip installed on it (ALS and LC), stage 1.
It's been already couple months like I'm fighting with weak voltage on ECU. Stu from MSD has been a real help but I just can't ask him directly with every problem I have

I have started my fight with voltage as weak as 11.8 on ECU under high pressure. After I removed orginal immobiliser and alarm, clean connections, made additional earth strap directly from battery and make new wiring for fans with separate relay for each fan I have found that ECU on idle (cold engine) has fallowing voltage:
everything turned off - 13.98V
with light ON - 13.71V
with light ON and one fan - 13.54V
with light ON and two fans - 13.36V

On battery I have fallowing results:
with everything OFF - 14.26V
with light ON - 14.08V
light + fan1 - 13.89V
light + two fans - 13.70V

When I turned ON absolutely what is possible to turn ON I had voltage on battery as weak as 12.8V.

I have checked all the basic fault according to this tread:
https://passionford.com/forum/genera...-readings.html
and the only one I have found is weak voltage on ignition trigger, pins 24 and 25. According to the tread mentioned above i should have at least 4.5V while I have 3.42V

The questions is:
1. Is the voltage OK and if not where is fault? Alternator has been renewed last year!
2. How to solve weak ignition trigger weak voltage?
3. What voltage should I expect when lights and fans are ON?

Will be glad for help!