Arrived outside for no cooling. Customer said that the air handler turns on just no cold air and the fan outside does not turn on referring to the condenser. Went outside after turning on the unit to look at the condenser and the condenser was not on it was not receiving its 24 volts. Went inside to the air handler to check the wiring inside the wiring looked me and tight. 24 volts for being sent outside to the condenser but the condenser was not receiving it to the contactor. Went back outside and looked at the wiring for the contactor and traced the 24 volts, one of the wires at 24 volts was not inserted into the wire not correctly. Since one of the condenser wires wasn't inserted into the wire not correctly it resulted into the wire being isolated making no contact. Twisted the 24 volts wire with the corresponding wire with the wire nut and made sure it was secure. Then turned on the unit with a thermostat calling for cooling and the condenser turned back on.