RV Repair: coleman rv mach unit, race car trailer, rv unit

Question
I have a coleman mach rv unit on my race car trailer modle[8330-715] and the compessor will run for 4 min and then turn off for 6 min ,time after time,[some times 1 min on and 10 min off] we are gitting good voltage to it , and the air [when it is on ] gets down to around 40deg [cold],we checked  the thermastat and is woorking like it should . I think it may be the compessor going out, may be kicking the thermal in it?  
I cleaned the fileter and took the cover [on top] off the unit and cleaned the cold side and the hot side of the cooling fins.
any ideas?

Answer
Tim, What is the amp draw when it is running? This will determine what the trouble is. It should be around 10 to 14 amps. If it is way low it may be overcharged which would be a rare thing for Coleman. How did you clean the fins? If they get plugged and it starts to freeze up there this will also shut the compressor off. Check these things and let me know. Also check to make sure that no refrigerated air is getting into the intake. This will cause things to happen. I will wait to hear from you, Bill