Carrier split unit only cools for first 10 min. after start up. It's a older unit could it be low on freon? It stopped heating as well. What should I check the heat pump or the compressor or could it be a loose 24 volt wire from thermostat I want to try and fix it myself before a pro. Rips me off 60 bucks just to look at it. By the way it has a new filter in the return and the coils have been cleaned outside but they did freeze up before that.

If the lines froze up outside it sure seems like its low on ref. but its also possible if there is a kinked line , check visually that nothing is crushed or restricted

I want to try and fix it myself before a pro. rips me off 60 bucks just to look at it

Well I would not call it a rip off since they have to earn a living doing repairs that others are not capable of.

After the 10 minutes run time what happens? Does the entire unit shut down? Does the outside fan keep running but no cooling is being done? More info needed.

Operate system in the heating mode and observe the outdoor unit. If bands/rings of frost appear on the coil, the system refrigerant charge is probably low.

After 10 min. of cooling it just blows warm air and it seems everything else is still running.

I want to try and fix it myself before a pro. rips me off 60 bucks just to look at it

Well I would not call it a rip off since they have to earn a living doing repairs that others are not capable of.

After the 10 minutes run time what happens? Does the entire unit shut down? Does the outside fan keep running but no cooling is being done? More info needed.

After 10 min. it just starts to blow warm air and everything else seems to be still running.

If everything is still running like the fan on the outside unit etc then the compressor in the outside unit must stop working after 10 minutes. How long does it take to start cooling again OR what do you do to make it start cooling again?