Looking at your wiring diagram, the icemaker is wired through the light switch. So when you open the door it stops power to the icemaker and the noise stops,push the light switch and it starts back up again.
A lot of times the motor, or module will go bad in the icemaker causing somewhat of a grinding noise like it is trying to do something but cant. 99% of the time it is best to change the whole icemaker to avoid further issues but sometimes you can just change the module depending on the condition of the rest of the icemaker.
is there a ballast or a starter? if there is a starter (little silver metal or white plastic can), then replace the transformer inside the lamp housing. if there is a ballast (long black rectangle with many wires) and you replaced that and the lamp, then there must be a power drain in the unit somewhere.
www.fixya.com/support/p22955-true_gdm_12_refrigerator_commercial Recent True GDM-12 Refrigerator Commercial questions, problems & answers. ...Where is the temp control on the older (14 yrs or so) on GMD-12? True ..
My Gdm 12 was doing the very same thing. Remove the from grill plate by taking out the 4 screws below the door. This will expose the compressor mounting plate . While the compressor is running, and is at its loudest, loosen or tighten the two front hold down bolts until the noise goes away. Most likely, when you cooler was moved or transported off the shipping pallet, it was bent slightly allowing contact between the bottom of the compressor, and the mounting plate. Hope this helps.
If the cooler has power, the condesor fan (bottom) and evaporator fan (top) are spinning put your hand on the compressor. Do you feel a vibration? if so, you probably have a refrigerant leak. If not (if its clicking or nothing at all) its a compressor issue.
I will tell you what the factory says. Get a reclaimer and remove the remaining refrigerant from the system. Put your vacuum pump on the system and finish removing the noncondensibles from the system. Take a scale that weighs in ounces and weigh in the exact charge stated on the spec. tag that gives you the model and serial number and refrigerant type and charge. If you just try to put some gas in you will have a refrigerator that builds up ice on the coil, wont shut off, makes bad sounds, and has compressor problems. Hope this helps and good luck.
If the humming last 3-5 seconds then makes a faint click sound and stops humming for a minute or two. Then resumes the hum again it may be your compressor locked down. Stuck. Most likely it is just a bad start capacitor not kick starting the compressor. A $6 part.
By not hearing anything but the fans I would have to say the compressor is not running. Pull the cover off so you can access the condenser area where the coil and compressor are located. Check the coil and ad make sure it is clean. Then feel the compressor and find out if the compressor is hot. If it is hot and the coil is dirty/dusty I would say it was going off on high head pressure/temperature. Clean the coil and let the unit sit off for a while and then try running it. If it is cool then it may have an issue with the refrigerant or other things like maybe start componenets.
hi,this is how i fixed mine ,i took off the light tube and the little silvercup next to the light (capacitor) took them with me to home depot to match the numbers and sizes it took me about two minutes to find them, the capacitors come in silver and plastic housing and they come in pairs but not expensive,good luck.