We purchased a used condensing unit and had it installed by a supposed licensed a/c tech. It is a Lennox, 5 ton, originally did not have a circuit board with lights but the owner upgraded it and the attic unit with an igniter and pre ignite fan. The air handler and heater are working, but the a/c tech said that he only heard a few clicks when he tried to start the out side unit.

I looked at it and it has what looks like 2 sets of contacters, a large one and a smaller one. The smaller one has power to it. But when I push in on the contacters nothing happens, and there are no lights lit on the circuit board. The seller guaranteed the unit was in working condition, but we waited 4 months to install it. Any idea what we could check?