RAM 2500 Truck 4WD V10-8.0L VIN W (1997)
Control Assembly: Testing and Inspection
Heater-A/C Control Assembly Vacuum Test
1. Connect the test set vacuum probe to the heater-A/C vacuum supply (black) tube in the engine compartment. Position the test set gauge so that it
can be viewed from the passenger compartment.
2. Place the heater-A/C mode control switch knob to each mode position, one position at a time, and pause after each selection. The test set gauge
should return to the 27 kPa (8 in. Hg.) setting shortly after each selection is made. If not OK, a component or vacuum line in the vacuum circuit of
the selected mode has a leak. See Locating Vacuum Leaks in the Diagnosis and Testing.
CAUTION: Do not use lubricant on the switch ports or in the holes in the plug, as lubricant will ruin the vacuum valve in the switch. A drop of
clean water in the connector plug holes will help the connector slide onto the switch ports.
