Our troubleshooting problem involves a split system heat pump in which the outdoor unit is operating in an 85°F ambient, and when you arrive in response to the customer’s no cooling complaint, you find the indoor fan operating normally, and you also note that 240 volts is read at L1 and L2 of the outdoor unit. (Click here for a PDF of the wiring diagram.)
As your next check, you test for the required control voltage at the Y and C thermostat connections because you note that the compressor and outdoor fan motor are both not operating and are cool to the touch. Your meter shows 24 volts at this test point, but 0 volts at the contactor coil. A check at the low-ambient control also shows 0 volts, and a check at the high pressure switch shows 24 volts.