I have a A/c unit that it works fine no issues there but when it hits the thermostat temp it wont shut off it keeps on running. I even did a test. I put the thermo at 76 degrees and checked it later the temp was at 70 degress. I have already changed the thermostat and still same issue. Now what it also does is that when I have it on the off position by me manually turning the a/c off at the unit it self ImageShack® - Online Photo and Video Hosting . The fan turns on and it starts running. Today I opended a cover that its about 8x8 in size to look inside of it and see what was there. after doing that and putting the over back on my screw driver slip and hit the over and the fan turned on by its self. If you look at the pictures you will be able to see what I am talking about. ImageShack® - Online Photo and Video Hosting
You need to trace the control as well as power supply using a voltmeter and the electrical diagram to find out what exactly went wrong. If you are not comfortable with working with electricity it is better to get someone else to check it for you.
I acutally got it fix. apperantly I have a 2 wire system. and the thermo has to stay on heat and just change the mode on the unit itself. then the thermo will turn it off and on. it works.now thanks for the help