Yhodah
I have a 17kw 2007 or so Generac. The unit failed to come online with testing the main breaker. It would crank but would not start. On manual it will crank and start quickly. New spark plug, and battery did not fix the problem. If after cutting the main breaker while the unit is cranking and I turn the power on, the generator starts but on turning the breaker off it will not disconnect from the service line. In manual with the transfer switch moved down the unit powers the house normally.

15b voltage with power on is 12.8v but when it is cranking on cutting the breaker the voltage is 6v. In the manual start position it remains 12.8 . I assume there is not enough energy to activate the valve to supply ng on auto. Transfer switch operation is normal with grounding the 23 lug. I have not done a manual test of the transfer relay yet.

I looked through all the posts here and did not find this described. Thanks in advance for any advice!

In addition I get the check battery fault on test of the automatic function. Battery voltage is good.
Quote
78buckshot
I would start checking ALL of the grounds in the generator, typically all black wires labeled zero. Also check the 12volt hot connections, make sure your battery terminals are bright and snug. Maybe even have the new battery load tested, your dropping voltage somewhere.
Quote
78buckshot
12.8 volts is low for a system that is charging, normal would be 13.5-14.2VDC. 6 volts is way too low for the cranking voltage, normal would be 10.5-11.4VDC, generac specs say no lower than 9 volts while cranking.
Quote
Yhodah
Fixed it. Thank you! Green ground attachment at the right rear motor mount had come off. Reattached and it immediately works properly! Thanks buckshot!
Quote
78buckshot
Sometimes we get it right, your welcome.
Quote