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HomeRepair HelpMars Central A/C RepairMars Central air conditioner compressor won't run Repair
Mars Central air conditioner compressor won't run
Won’t your Mars central air conditioner compressor run? The compressor may be defective or worn out, although the other electrical parts should be checked first. The compressor is the most likely listed cause, followed by a failed start capacitor, defective contactor, failed run capacitor, capacitor, or dual run capacitor. A bulging or leaking capacitor may not hold and release its charge, while a contactor with burnt contacts or an open coil can keep voltage from reaching the compressor. These problems can cause an AC compressor not running, an air conditioner compressor that won't start, or a central AC compressor not working even when the indoor blower operates. Testing continuity and capacitor performance requires a multimeter, but the condensing unit contains hazardous 240V line voltage. Turn off power at the disconnect box and circuit breaker, and do not test or replace energized parts. Any repair involving refrigerant, the sealed system, or compressor replacement requires EPA 608 certification and a licensed HVAC technician. Enter your Mars central air conditioner model number to find the exact replacement compressor, start capacitor, contactor, run capacitor, or dual run capacitor for your unit.
01 - Mars Central Air Conditioner Compressor
The compressor is a pump which compresses the refrigerant and circulates the refrigerant through the evaporator and condenser coils. If the compressor is defective or worn out, it likely won't run. However, this isn’t usually the case. Before replacing the compressor, first check all of the more commonly defective components. If all of the other components are working properly, use a multimeter to test the compressor for continuity. If there is an open circuit, the compressor is likely defective.
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Highly Likely
02 - Mars Central Air Conditioner Start Capacitor
A start capacitor is often used to cycle on the compressor. If the capacitor burns out, the compressor may not run. The start capacitor can be tested with a multimeter to determine if the component can successfully hold and release its charge. If the capacitor is unable to hold and release a charge, or is bulging or leaking, the capacitor will need to be replaced.
Common
03 - Mars Central Air Conditioner Contactor
The furnace control board sends a low voltage signal to the contactor. When the contactor receives the signal from the control board, it closes the circuit, sending voltage to the condensing unit components. If the contactor is defective, it can prevent the compressor from running. To determine if the contactor is at fault, use a multimeter to test the contactor coil for continuity. If the contactor coil does not have continuity or the contacts a on the coil look burnt, replace it.
Common
04 - Mars Central Air Conditioner Run Capacitor
A run capacitor will power either the compressor or the fan motor (a dual run capacitor will power both). If the capacitor burns out, the compressor may not run. To determine if the run capacitor has failed, test the capacitor with a multimeter. If the capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
Less Common
05 - Mars Central Air Conditioner Capacitor
The capacitor provides voltage to the compressor to start it. If the capacitor is defective, the compressor won't run. To determine if the capacitor has failed, test the capacitor with a multimeter. If the capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
Less Common
06 - Mars Central Air Conditioner Dual Run Capacitor
A dual run capacitor will power both the compressor and the fan motor. If the capacitor burns out, the compressor may not run. To determine if the dual run capacitor has failed, test the capacitor with a multimeter. If the capacitor is unable to hold and release a charge or is bulging or leaking, replace it.
Less Common
Frequently Asked Questions
Why is my Mars central AC compressor not running?
How do I test a central AC start capacitor or run capacitor?
Could a bad contactor cause my AC compressor not to start?
Should I replace the compressor if my air conditioner compressor won't start?
How do I find the correct Mars central AC replacement part?
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