AC roof unit stops cooling after rain

need freon

Don't really understand what you mean by roof top duct unit .if it's a roof top unit and water is leaking down your vent then you have a clogged drain line .

Dirty coil wash outside unit with water and change indoor unit filter

If it's leaking inside where filter cover is, then real good chance the drains being plugged is the only problem. If water (condensation) not running off roof when operating in cool mode, then I'd bet drains, which are located under unit on roof, and you should see them sticking down like buttons. They have a hole in side that needs cleaning with a pipe cleaner or similar to open them up. If need be, shut off power to unit and remove top cover on roof unit and look for the drain holes in base, and clean them out. If water comes in while raining, but AC not running, then it's gasket. That is remedied by removing ceiling assembly (just screws) and 4 bolts that pull/hold the upper and lower assemblies together, unplug wiring to upper unit, and simply lift it off, change gasket and re-install. Tighten those 4 bolts equally when gasket is aligned properly over hole, only until gasket is approx 1/2, original thickness. Plug harness back in and your done. (about an hours work.) Only other thing that may be wrong is styrofoam drip tray for cooling unit, under cover on roof may have a crack , allowing condensation to leak in. If that 's the case, you can try to find a sealant compatible with styrofoam to seal those cracks.

two things you may try, relocate ambient sensor to colder place, remove it from front bumper, and connect the two wires on refregerant temp sensor located @ rear of compressor, be carefull and observe your a/c system after doing this

Disconnect power to the unit and reconnect. If "stop" is still on the display you will probably need a qualified technician to trouble shoot. The best mode is the snowflake (cooling). The rain drop is dehumidification which can cause condesation on unit.

you have to open the unit up or atleast see if the fan is failing. The blower motor is usually a double shaft and cool the compressor and also blows the air across the evaporator. Look for the air to stop blowing then the compressor to shake from overheating.

Check the breaker for the AC

Shut off the cooling and leave the fan in the on position. If the A/C cooling coil is frozen over it will stop air circulation. After you shut the cooling off look down through the fan on the roof top unit and look for any sign of ice on the big line going to the compressor. This would be a sign of the frozen A/C coil. After about an hour or so you should start to feel air movement.

To prevent the coil from freezing up operate the fan in the on position while the air conditioning system is in the A/C mode. Not automatic.

If your condenser blow air up through the top of the condenser and you are concern about rain water affecting the unit.

You can install a roof or rain hood about 4ft above the unit to keep the rain off, The unit must be able to blow air off without causing Hi head pressure to affect the unit, The condenser must breathe or desipate heat freely.

Tell me if your question answered or if it works for you.