Diesel Data: Automotive Repair

The Blower And Heater Controls And The A/C System Do Not Work




The blower and heater controls and the A/C system do not work

Probable cause: The HVAC control unit has malfunctioned, or has lost power or ground

Do the HVAC control power and ground circuit troubleshooting HVAC Control Power And Ground Circuit Troubleshooting (Without Climate Control)

Also check for

HVAC DTCs How To Troubleshoot The Heating And A/C Systems (Without Climate Control)

Also check for

Blown fuse No. 36 (10 A) in the under-dash fuse/relay box

Also check for

Poor ground at G503

Also check for

Poor or loose connections at the terminals