Anybody know why output 1 would cycle off for 1 second about every 5 seconds. No lights showing but inverter light on. No amperage out so its not overloaded. Input voltage is 13.3 and output is 120 at 0 amps. System has worked fine since August of 2019. Traveled yesterday with it off and pulled into camp and this was happening. We did try killing the 12 volt supply power. Didn't help.