I would think that beyond a capacitor you would need a resistor and a diode prior to it. The diode would keep the capacitor voltage from escaping back to the starter motor. The resistor would reduce the inrush current when power is applied. The resistor and diode would take the full current all the time.
Winner winner!!
They tried a number of things (the trigger, running power directly to the battery, etc) none of which worked. In the end they kept the power running directly to the battery and added a capacitor, resistor, and diode. Works like a champ. Thank you.
And the shop was great, even though they had to do an extra 6 hours of work, they didn’t charge me for the labor or the additional parts. Everything was covered by my initial $300 quoted install price. It was annoying but I’m pleased with the result.
I’m not one for endorsements, but....Bonnie & Clydes Car Audio in Dallas if anyone in my area is looking for a shop that will work through a problem and make it right.