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Andy, Truck Diagnostic Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1673
Experience:  International and Isuzu trucks , International, Maxxforce, Cummins and Isuzu engines, Diagnostic and electrical troubleshooting specialist , Hvac and truck /trailer refrigeration troubleshooter
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1999 Sterling dump truck. A/C problems. A/c blows cold then

Customer Question

1999 Sterling dump truck. A/C problems. A/c blows cold then start blowing hot. gotta turn off and wait a minute then turn it back in then it blow cold again
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Heavy Truck Mechanic I'm going to connect you with knows all the tricks and shortcuts.
Customer: ok
JA: Are you fixing your truck yourself? What have you tried so far?
Customer: We changed hi pressure switch, low pressure switch, and blower motor resistor
JA: Anything else you want the truck mechanic to know before I connect you?
Customer: Thats it and its full on Freon
Submitted: 1 month ago.
Category: Medium and Heavy Trucks
Expert:  Andy replied 1 month ago.

Hi there . My name is ***** ***** Sounds like you may not have enough air flow going through evaporator causing it to ice up. Have you replaced the fresh air filter ? Or removed it to see if it is any better? Also , does it seem to cool better when in Max ac ? If so , this proves it because in that mode , it was recirculate the air inside and use a different filter.