Replacing temperature control on a True beverage cooler

Metalfrio beverage cooler throwing off a 77 error code,
I checked evaporator fan and it is running.
I see line coming to evaporator coil is cooling but. Evaporator Fan is running but Refrigrator is not cooling down.

Sounds like it may be cycling off hard due to high discharge pressure. Make sure the condenser under the unit is clean and the fan motor is running. It shouldn't be running 60f. A lot of people make the mistake of checking temperature with an empty unit. Put a couple of gallons of water in the unit so that the temperature evens out. These units do NOT run based on air temperature but rather on inside coil temperature. That will swing wildly with no load in the unit.

PDF]True Manufacturing Company, Inc. - Fixitshop.com

https://fixitshop.com/manuals/TECHNI~1.PDF

Top Removal for TBB and TDD ... Top Removal for Various Coolers - TSSU, TWT, TUC ... End Cap Replacement-T-Series Swing Door ... GDM 2 Door Cooler IDL Light Diagnosis ... If you keep the Condenser clean you will minimize service ...

[PDF]installation - True Manufacturing

https://www.truemfg.com/assets/...Website/TDB_TBB.../tbb_english.pdf

Your TRUE cooler when properly maintained will give you many years of trouble-free service. TO LOCATE REFRIGERANT ..... Removing bracket from skid. Removingbracket from cabinet. 1. 2 .... tab holding the door cord slides out the back. ... The switch is located on the front of the evaporator housing toward the front of .

Sounds like a faulty temperature probe or faulty temperature control circuit. Some modify their unit with an external temperature controller. It does require knowledge of wiring to perform the modification. There are detailed notes, images, etc provided by psychodad at
Thread Danby Kegerator Improvements Part II

If it needs gas it has a leak. These coolers generally don't come with gauge access ports and need to be silver brazed into place. These systems have a critical charge and will not operate right unless the exact ounces of refrigerant are in the system. The temperature controls measure coil temperature instead of cabinet temperature. The wrong charge makes them run and run and they cant control temperature. Hope this helped.

Are you referring to the compressor not shutting off down below or the evaporator fan inside the cooling area not shutting off? Evaporator fan always runs the compressor is controlled by the thermostat you could have a bad thermostat if the compressor never shuts off.

You will need Adobe Acrobat Reader to view these documents. The Adobe Acrobat Reader is available as a free download. Get Adobe Acrobat Reader Click Here=> KUWA244PBS Parts List
and here=> KUWA244PBS User and Care Guide
If you should need the service manual you will need to cant me here=> HERE Reason is Whirlpool does not allow me to publish the SM here.

The beverage center and wine cellars have a temperature display for each zone. 12 volts

AC is supplied to the display board from a transformer in the unit compartment. The displays are only temperature displays and have nothing to do with any cooling function. A thermistor is used to sense temperature for each zone. The thermistor for the bottom zone is located inside the lower portion of the separator. The thermistor for the top zone on the wine cellar, (mid zone on beverage

center), is located in the upper portion of the separator. The thermistor for the beverage center upper zone is located on the inside of the 2-piece evaporator cover. It is on the right-hand side.

The mid temperature for the bottom zones on either unit are 60? Fahrenheit plus or minus 5 degrees. The mid temperature for the mid zone on the beverage center and the top zone

on the wine cellar is 45? Fahrenheit plus or minus 5 degrees. The mid temperature for the

top zone on the beverage center is 38? Fahrenheit plus or minus 5 degrees. I think at tis time you should check each section with a pocket size digital thermometer to cofirm tha the mechanical thermostat is within calibration. Click Here=> 4344690 Temperature Control

Click here for a=> KUWA244PBS Beverage Center Wiring Diagram
I believe the problem may be in the PCB transformer shown at the bottom right corner of the wiring diagram. It is possible o change the transformer but I have not been able to find the board that powers the LED temperature readouts. If needed let me know and I will call Whirlpool mfor you, Thanks, Sea Breeze

Inside the cooler is the evaporator fan usually right in the middle behind a cover. As it slows down you have less circulation and ice forms quicker and cooling is diminished. Sounds like it is going out.

A starter may be located in the top area inside the cooler. Not all true coolers have starters. Check the connections where the light pins slide into. Also may need new ballast.

BY to I take it yu mean top area inside cooler. If that is the case and yu are sure the drain is clear it could possibly be one of the following.
1: rusted/ corrodid evaporator drain pan
2: coil in cooler partially frozen