Where can I find a wiring schematic for Frigidaire AC wall unit FRA125CT1

A humming sound coming from your Frigidaire AC wall unit after it has been powered off could be due to a few different reasons.
I can provide some potential explanations and troubleshooting steps to consider:

• FAN MOTOR
• THERMOSTATE DELAY
• ELECTRICAL ISSUE
• REFRIGERANT FLOW
• OTHER MECHANICAL ISSUES

Is this an electric unit or does it run on fuel?

Good morning friend, I appreciate your post!
I understand that you are trying to diagnose and repair your Frigidaire air conditioner, FAC107P1A. Could you describe what your appliance is doing so that I can assist you better in pinpointing the problem before any additional steps are taken. I have provided the link to where you could find additional information regarding a manual for your air conditioner as you have requested as well. I look forward to assisting you. -Matt
Frigidaire Manual Search Results

It could have a defective switch, thermostat or compressor. Any of these would cause the same symptoms. Also a loose wire at a connection point.

If the unit is not producing any cool air, then you must see if there are replacement parts available for this unit from your manufacturer. Some units, this small, do not have many parts that can be purchased and repaired.

There is a drainage hole on the outside of the window unit. It is blocked. Remove power from the window unit. Unclog with a wire coat hanger.

Hi,
The drain holes in the bacl are plugged with dirt...
pull the A/C out and check for the blockage and remove it so that the unit will drain properly.
The drain holes are usually in the back corners...

heatman101

window units slide into an outside frame section
there is a hose attachment area at the back of the ac unit proper that a hose can be attached to
and there should be a section in the frame that allows the hose to be fitted to that ac unit proper
the unit should be mounted so that it actually slopes slightly down at the rear so water can collect at that drain point
there are adaptors that should have come in the packing box for hose attachment
if not, many people use white poly piping or electrical conduit with suitable elbows to collect the water at the hole and pipe it back to the wall into a bucket and the collected water used to water plants and gardens

This unit is a 220 volt ac unit. 12-2 wiring is usually for 120 violt circuits?

Amps: 22.2 / 20.0

Watts (Heat): 4900 / 4000

Watts (Cool): 1650 / 1625

Amps (Cool): 7.7 / 8.3

Voltage Rating: 230V / 208V 60Hz

Power Cord Length: 5' (6')

Horsepower (Cool): 2.49

Plug Type: LCDI 6-30P

http://www.frigidaire.com/Home-Comfort/Air-Conditioning/Window-Mounted-AC/FFRH1822R2

hope this helps?