HVAC Bad Megger readings on Trane were due to crud

Compressor had bad Megger Supco MM500 readings until wire entrance area vacuumed and washed and dried. Katrina salt water marsh grass was still under this cover. Via the Supco MM500 original reading BAD less than 20 meg. After vacuuming 100 megs. After washing and drying 300 to 400 megs.