Well, if it was up to me, there is a coupon for a free a/c check. So i would recommend that. Then i would hook the guages up to determine if you are low on freon or if there is a elec./sensor problem. After that i give you the option of what to do based on the problem, and give you a price. If its just low, and you wanted to charge the system and put dye in it, i would evac. the system, vacuum it down, and let it sit for a while. This will give any leaks a chance to present themselves as the vacuum on the system would diminish. After that, i would charge it with dye tracer and tell you to come back in a day or two to find the leak. You get the picture.