I thought you could run both A/C units when the genset is running...
I do not have shore power at my storage.
But I could not make it work... I looked at my switch above the kitchen... and it seems I can run front or rear, but not both...
Am I doing something wrong?
So, I did a search!
Some say you can and others you can't...
I found this thread, but came away confused!
I will quote Brad in post #12 who seems to say his '84 310 with the same Kohler 7000 I have will do it...
"On our 310 (which should be about the same as your 345) when you start the genset there is a control box that has a time delay transfer relay that approximately 45 seconds after starting the genset will isolate the incoming shore line power from the motorhome (if you're still hooked to shore line) causing the motorhome to receive power only from the generator.
There is a second transfer relay that is located under a closet close to your genset. This relay is used to isolate the rear air conditioner from the circuit that feeds the rest of the motorhome 120vac wiring. Your genset has two separate power feeds each has its only little circuit breaker mounted on the genset.
What the genset isolation relay does is force the the second circuit from the genset to power only the rear air conditioner. When you are on shore power the isolation relay is de-energized and power to the rear air comes from the rotary switch in the kitchen. When the genset starts up 45 seconds later the rear air conditioner isolation relay kicks in and provides direct power to the rear air conditioner from the second generator circuit.
In other words when the rear air conditioner isolation relay is off (shore power) the rotary switch determines when the rear air runs. When the genset is running the rear air conditioner isolation relay sends genset power to the rear air conditioner isolating it from the rest of the motorhome.
This only works when you are running on the generator. If you turn the generator off an reconnect to shore power you can only run one air conditioner at a time.
I was told by the generator repair place the best way to run two air conditioners on one genset at the same time is to set one of the air conditioners to the FULL cool position so that it runs ALL the time. You then use the second air conditioner to modulate the temperature in the motorhome. In other words make sure one always has its compressor running (i.e. cooling mode) and set the temperature setting on the second generator to turn it on and off as required to keep the temperature where you want it.
If you don't use that method it can be real hard on your generator especially when both air conditioners turn their compressors on at the same time. The starting current for an air conditioner is a LOT higher than its running current.