Wheather is getting warmer up here, here are some air conditioner season start up maintenance and tips.
Ensure air filter is clean, if ac is run with a dirty filter the evaporator (indoor coil) can ice up and system will fail.
Ensure the fins on the outdoor unit are strait and clean, you can get an inexpensive fin straightener at a hardware store, looks like a comb
Ensure there is a clear path for air into (sides) and out of (top) the condenser (outdoor unit), check bush/tree growth around unit
Ensure balancing dampers (handle attached to duct with a wing nut) are open (handle pointed down the duct not across) airflow restriction will ice up indoor coil
Check the condition of the insulation on the large copper line going from the outdoor unit to the house. if it needs to be replaced ask for "armaflex"
When the "cottonwood" trees release their fuzzballs check the fins again and hose off if necessary.
Remedy for a frozen evaporator:
If you run your air conditioner and the air coming from the register seems to have a weak flow go to the thermostat, turn the mode to off and the fan switch to fan on. run the fan for an hour or so, and feel the air coming from the register, if the flow improves check for an airflow restriction (dirty filter, closed registers, closed dampers, air returns covered by furniture artwork etc.). Running the fan with system off melts the ice off of the evaporator, DO NOT turn on the heat mode.
If you are unsure of the problem, or your abilities do not hesitate to call a technician, and safety first
Hope this helps, any other HVAC questions feel free to ask