John-
It sounds like the A6060 control board (brain) is doing a delayed shutdown of the generator after you turn CB1 to "ON". The info below is copied out of the maintenance manual, and it describes various problems that can shut the unit down. Note how some are delayed shutdowns, and some are immediate. Low oil pressure, high oil temp, and throttle stepper motor failure can also cause a shutdown, but it doesn't sound like any of those are happening.
One thing I would do to help diagnose this is disconnect the inverter AC output from the camper entirely. That way you eliminate the possibility of a problem in the camper or PTS causing the shutdown. As copied below: "If the inverter senses a short circuit on the AC output side it will automatically shut the generator down", but I think that's an immediate shutdown, not a delayed like you are seeing. But, you also don't want the electrical appliances and systems in the camper being damaged by the generator while you try to fix it. You could rig up a temporary connection to a single duplex outlet until you figure out what's wrong. Use a fan or a shop light to test the output if needed. A small space heater or hair dryer can be used to put a load on it if you get to that point.
What it sounds like is happening is:
1- Engine starts and runs normally with CB1 "OFF".
2- Turning CB1 "ON" causes inverter to produce AC output, which is seen by PTS and it prepares to switch camper to generator power.
3- There is something wrong (missing/faulty signal or voltage) between the generator and the inverter which causes the A6060 board to start the 5-7 second delayed shutdown.
4- The delayed shutdown occurs shortly after the PTS transfers, which makes it appear that the PTS is somehow causing the shutdown.
I would be looking at the connections and voltages between the generator and the remote mounted inverter, because "LOSS OF 12-PIN CABLE SIGNALS TO INVERTER" and "LOSS OF PS1/PS2 TO INVERTER" sound most like your symptoms.
The maintenance manual has some pretty good symptom-based trouble shooting tests, but you need to be able to use a Volt/Ohm meter, and work with electricity safely. It also has a procedure for running the generator with the inverter disconnected, and CB1 "ON" if needed.
ADDITIONAL SHUTDOWN FEATURES
The A6060 Circuit Board also incorporates the following
protective shutdown features:
LOSS OF 12-PIN CABLE SIGNALS TO INVERTER:
The generator will shutdown if the 12-pin connector is
disconnected from the inverter when CB1 is turned to
ON.
This shutdown will occur after approximately 5-7
seconds.
LOSS OF TIM1/TIM2 INPUT TO A6060 CIRCUIT BOARD:
If Timing Winding input is lost, the generator will
immediately shutdown.
LOSS OF PS1/PS2 TO INVERTER:
A loss of voltage from PS1/PS2 windings to the
inverter will simulate a 12-pin signal failure and cause
a shutdown when CB1 is turned to ON.
This shutdown will occur after approximately 5-7
seconds.
OVERSPEED OF ENGINE:
Overspeed of the engine will result in an immediate
shutdown. This automatic generator shutdown will
occur at engine speed above 4200 rpm.
SHORT CIRCUIT PROTECTION:
If the inverter senses a short circuit on the AC output
side it will automatically shut the generator down.
INVERTER OVERHEAT CONDITION:
If the inverter overheats, AC output will be shut off.
The engine will continue to run for approximately two
minutes and then shut down. The maximum ambient
temperature rating is 120°F.
DC LINK VOLTAGE GREATER THAN 600 VDC:
If DC link voltage exceeds 600 VDC, the inverter will
shut off AC power output.
DC LINK UNDER-VOLTAGE SHUTDOWN:
If DC link voltage drops below 100 VDC, the inverter
will shut off AC power output.
:):)
