Air conditioner doesnt work

What is your question?

3 Mechanics cant find whats wrong with 2 air conditioners in my 1997-98 GFMC Savana short school bus.3500.I bought the short school bus and converted it in to a vending bus by taking out all seats and put in cabinets shelving etc...There's one air conditioner of course that is part of the truck..the other hangs from the ceiling in the back ceiling..Both stopped working at the same time