Auto Air Conditioning & Heater Repair: air condition 99 blazer, electronic leak detector, freon

Question
I drive a 99 Blazer 4 door. The air conditioning has always worked great. Cools nicely and no leaks that I can see. This afternoon I went to lunch and it was great. Then an hour later I come back from lunch and it only blows hot air. Buy it does still blow something. One mechanic said that it was a leak and that they would need 200 plus tax just to find where it was. Then more to actually fix it. Another mechanic (my friend) said he thought it just needed coolant added. Do I go to the expensive guy? Is there a leak or is it just out of coolant?

Answer
FIRST I would stay away from your friend if he thinks FREON is COOLANT. This would scare the heck out of me if he does not know the difference.

If you need to add freon then there IS an obvious leak and this will require the use of an electronic leak detector in order to FIND the leak source.

I think you can find a cheaper facility to just find a leak that takes less than an hour.