AC Not Cold with Musty Smell
The air conditioning system is blowing warm air and emitting a musty odor when turned on. This typically indicates a refrigerant leak or compressor issue combined with microbial growth in the evaporator case.
Diagnosis Details
Possible Causes
Low refrigerant charge due to a leak (common on Silverado AC systems, especially at the compressor or condenser)
Clogged or dirty cabin air filter causing restricted airflow and musty smell
Mold or mildew buildup on the evaporator core from moisture accumulation
Faulty AC compressor or clutch not engaging
Related OBD-II Codes
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What You Should Do
First, check the cabin air filter and replace if dirty.
Then inspect the AC system for refrigerant leaks (use UV dye or electronic leak detector).
If refrigerant is low, repair the leak and recharge to spec.
For the musty smell, use an evaporator cleaner foam and run the fan on high with heat for 10 minutes to dry the case.
If the compressor clutch doesn't engage, test the refrigerant pressure switch and compressor relay.
Related Repairs
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
