Our A/C comes on and is cold then randomly it stops cooling. We can drive 1/2 hour, it goes off, then 1/2 hour later it comes back on.
We have changed the relay thinking that is the problem. System holds a charge so we know it is simply not freon.

Any ideas of how to DIY this problem?

 

I take it the compressor is kicking on, and off? There is a pressure switch in the system that is probably bad. You also might check connections at the comp[ressor clutch if it is the compressor on/off.