Furnace will not run when hooked up to electricity

check and test for short ----compressor - fan[s] short

• The completely automatic transfer switch monitors incoming voltage from the utility line, around the clock.
• When utility power is interrupted, the automatic transfer switch immediately senses the problem and signals the generator to start.
• Once the generator is running at proper speed, the automatic transfer switch safely shuts off the utility line and simultaneously opens the generator power line from the generator.
• Within seconds, your generator system begins supplying electricity to the critical emergency circuits of your home or business. The transfer switch continues to monitor the utility line conditions.
• When the automatic transfer switch senses the utility line voltage has returned at a steady state, it re-transfers the electrical load back to the utility line and resumes monitoring for subsequent utility loss. The generator will continue to run for an engine cool-down period of several minutes while the entire system stands ready for the next power outage.

https://www.dieselgeneratortech.com/generator-sets/Information-of-Starting-Battery-in-Diesel-Generator-Set.html

I would be checking the main breakers on the panel to insure one didnt trip when you added generator electric. is there a breaker on the outside line at the box you may be missing? Also keep in mind, although uncommon, breakers do BREAK and need replacing. are you competent enough to use a volt meter to check the hot leads on the box and at your unit breaker box to insure you are getting power into the unit? In some older units the switch between land power and generator power was to manually throw breaker switches but automatic processors have replace them now... I would say start at the residential plug in and verify power is where it should be along the route of the supply cord...from the meter forward... if you have a converter plug, say from the 220V 30 amp that you are probably drawing down to 110V household, stick that on the meter and plug in your toaster to insure there is power coming in....IF YOU DONT HAVE A METER AVAILABLE... otherwise...test test test... your generator probably broke a circuit somewhere... now just to find it..

IT MAY BE A TRANSFORMER PLUG TO ALLOW USE OF ELECTRICAL POWER TOOLS OR ACCESSORIES OUTSIDE OF THE MOTOR HOME SUCH AS A RADIO OR LAP TOP. I CAN'T TELL YOU WITHOUT EITHER SEEING A PICTURE OF IT OR A BETTER DESCRIPTION OF IT. IF THE PLUG IS SEPERATE IT COULD BE TO ALLOW YOU TO RUN A GENERATOR TO RUN YOUR LIGHTS INSTEAD OF USING THE BATTERIES FOR THIS.

Could be thermostat or safety switch(es) in the furnace. Are you sure that the pilot is staying lit? Are you sure the main burner is lighting? Are you sure the forced draft blower is running, and the blower-detection "flapper" switch is working OK? Any of these safety devices will cause the gas supply valve to close if they are not "satisfied" in a few seconds after the thermostat calls for heat. They keep your RV safe!

The AC typically uses the same blower as the heater to circulate the cool air. Sounds like it is working properly just turn it to cool rather than heat.

Go to the thermostat and access the fan mode. Change the mode to AU (automatic) then turn the furnace on and it should work normally. If the fan mode is in Hi or Lo the Ac fan will blow.

Your AC (air conditioner) would only run on AC (alternating current - shore power) so there would be a circuit breaker. Fuses are for DC (direct current - batteries).

That said, 16A is a very odd number for a circuit breaker (or fuse).

Your AC will only run if you are connected to shore power or have a generator. (Very large inverter and a lot of house batteries is technically possible but very unlikely and it wouldn't have been built that way).

If your AC actually draws 16A then being connected to a 30A outlet is fine, I have actually connected mine to a 20A outlet at home to test it but I made sure nothing else was turned on fridge, heaters, water heater etc).