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   I am new to the vending world and need a little help. I have a Cavalier 12-72 Pepsi machine that needs some cooling attention. I probably needs a new compressor or maybe a whole cooling unit? When you plug it in the the lower radiator doesn't get hot and the top one doesn't get cool, sorry i don't know what to call these parts. The one on the bottom is rusty and maybe it has a hole in it? Any help would be greatly appreciative!
                                                                                                                                                                    Thanks bv2

Hello & welcome to the site, the top cooling coil is called the Evaporator & the lower heat-radiator is called the Condenser.

first things first;

1.  does the compressor & the condensers cooling fan turn on? (they should turn on together)

2.   is the compressor actually running? (check this by temporarily stopping the condensers cooling fan   from turning by stuffing a rag into the fans blades [with the power off of course!!!] now listen for the compressors running or feel it with a gloved hand to see if it's really running. ( only use the rag-trick for less than five minutes at a time, or you'll over heat the fans motor)

3.   now if the compressor doesn't turn on, is the thermostat up by the evaporator turned all the way to Max cold? ( this is the highest number on the dial or fully clockwise if the knob or shaft isn't marked) it may be stuck, test this by turning it fully COUNTER-Clockwise until it clicks off, the slowly turn it back clockwise until you hear or feel it click "On" if it doesn't "click" on, try rapping the end of the shaft with the handle of a plastic screwdriver ( just a nice sharp tap, don't beat it) & double check if the compressor turns on ..

4.    If the compressor still doesn't turn on & start running, see if there is small electrical plug that the compressor uses to plug itself into the wiring harness, unplug it & using an extension cord, plug it into the test cord & see if the compressor will now run. if it does , you may have a bad thermostat or a wiring issue between the thermostat & the compressor, if it doesn't run. you may have a compressor issue.

try the above tests & we'll go from there

thank you johnie g i will check all of those things tomorrow and i will get back with yall.

johnieG I checked those things and the compressor is running and the thermostat is working, what do i need to check now?

Good, then if the compressors running, does the smaller line from the compressor leading to the top of the condenser feel warm to very warm to the touch? ( use caution, as this high side line can get over 150 degrees-F if the compressors been running a while.)  if not & it is cool to the touch, then either you are low on freon, or you may have a plugged capillary tube or other source of a plug in the high side, such as a filter/dryer, or a blocked filter screen*

( *= on earlier systems, like many Vendos, this micro-fine stainless-steel screen is located inside the bottom of the tubing that exits the lower line of the condenser coil just before it is brazed to the capillary tubing, in this case you may not have a filter/dryer on the high side)

The only way to check for proper system pressures is with an R-12 gauge set & the system will either have to have service valves on the lines, or you can use the clamp-on self-piercing line taps to test the system.

Thanks for the help, i will check the freon and get back with yall.
                                                             thanks bv2

Ok guys i got 16oz of r12 in the machine today and its cooling, i guess i will see how long it will last. So for so good!
                                                                                                        Thanks again for all the help!
                                                                                                                           bv2                     

 did you already have a can of R12 laying around or did you have to buy, it, If so what did it run , that stuff is getting very expense.

My friend had a old cylinder that had 16 oz left in it, i didn't know you could even buy it any more. I pluged the machine about a hour ago and the temp is in the 30's.

Ok guys the machine has been running all day and cooling at 32 degrees with the thermostat on the coldest setting but the compressor hasn't shut off, you can turn the thermostat off and the compressor will go off, you can turn the thermostat to the lowest setting and it will cool to 40 degrees and the compressor still doesn't shut off. what to check now? Any help would be greatly appreciated.
                                                                                                                     Thanks bv2

Question, do you have frost all the way up the suction tube back to the compressor?  I was thinking that 16oz of R-12 is a bit much for that size of a machine, the  system is basically the size of a vendo V90 & that only takes 12-oz. of freon...did your machine have a specification tag that told you how much freon to charge the system to?  just curious... :oh:

Insofar as your T-stat issue, if it were bad I couldn't see how it would regulate the temp between 40-32/deg. Fahrenheit,  it would be the same (too cold temperature all the time regardless of the dial setting), but if the thermostat was be doing it's job, then the temp would vary with the dial setting, does the condenser fan shut off when you turn the thermostat off? (or just the compressor? )

The fan inside the cabinet runs all the time. The fan by the compressor and the compressor cycle with the thermostat.

Johnie there is a tag on the side of the machine that it calls for 16 oz of Freon. There is ice-frost on the line that we taped into back to the compressor and bubba is right on the fan in cabinet, it stays running when the t-stat is turned off. When the t-stat is on any of the cooling settings the compressor never kicks off?

       Is the capillary tube coming off the thermostat in a location where it senses the true temperature of the evaporator?

Moondawg the tube coming off the t-stat is bolted to the side of the evaporator. I hope i answered this right

Now that the compressor has run all day it will not get below 40 degrees and hadn't kicked off yet? Any thing else i can check? Guys i really appreciate all the help yall have give me!   
                                                                                                                           Thanks bv2

sounds like it is leaking freon look for signs of a leak