no spark in start
I should have some where near 10 volts. yes no?
Yes but cranking voltage at the battery with all plugs in,at summer-time temperature, should be more than 10.5v and holding for at least 15 to 30 seconds at this time of year. The longer it holds the bigger or the better, or the stronger, is the battery.
Prove your gauge is telling the truth. If good
Carbon-pile test the battery. If good
I'd say test the starter but I know of no better test than bolted to the motor and sucking electrons, as it now is doing. So then I'd suggest
Replace that ECU with it's high minimum-voltage requirement.
