You don't have to take your RV in a service tech for every inspection. There's a lot you can do on your own to make sure things are ready for the season ahead.
Quality & Efficiency - these are both linked to the condition of your filter. A clean filter in your AC will ensure efficient cooling and consistent operation. Give a solid inspection once you fire up the RV. During your travels there's a lot of foreign matter that gets kicked up and passed through the system. You'll want to check it weekly and keep it clean. If you're still running into issues with allergies even with a clean filter then you probably want to switch to an electrostatic model that will attract allergens and smaller particulates using static electricity. There's no sense in taking off on an RV camping vacation and being miserable due to poor air quality in your rig.
Inspect the Shroud - Check around the rooftop shroud on your RV. You would be amazed how easy it is to trap leaves, sticks, trash and other debris. Be sure to check inside the shroud for nests from birds, mice or dirt daubers. Sometimes you might even pull out some natural food stashed there by a resourceful squirrel. If your shroud is broken then replace it immediately. You don't want it breaking free and coming off when you're traveling down the road. A loose shroud may not need replacement and can likely be tightened - just be careful not to wrench to heavily on the anchor bolts or you risk cracking the shroud.
Gaskets - Inspect your gasket. If you're up on the roof inspecting the shroud then you might as well check the gasket. This gasket sits between the air conditioner and the roof. A failing gasket can allow water to enter through the roof. Since your RV is constantly exposed to the elements during your camping trips, the last thing you want is extensive water damage. If your gasket is more than 50% compressed then it's time to replace it.
Fan & Motor - When you inspect the fan and motor it should purr quietly. You should never hear rattles, vibration or loud humming noises. The fan blade of the motor should also turn freely.
Check the Coils - It's important to have your AC coils cleaned annually. Even a high quality filter still lets some smaller dirt and other particles through. This debris collects in the evaporator and condenser coils. It's recommend you take this task to a certified technician. They can also provide other services, like fixing and straightening bent cooling fins,
Avoid Motor Damage - When you're traveling, always run your RV AC on at least 30 amp power. Otherwise you risk damaging the motor. A 15v-amp adapter may not be sufficient depending on the AC system you have and likely won't get the AC up to full speed. Most RV resorts tend to offer full hook up sites with 50 amp power. Opt for those sites where you can get them.