Function Selector Valve Test
Place function selector knob in specified position. See FUNCTION SELECTOR VALVE TESTING table. Using a vacuum gauge, check vacuum condition at indicated vacuum port. If test results are not as specified, check for kinked or broken vacuum hoses. See Fig 1. If vacuum hoses are okay, replace function selector valve.
FUNCTION SELECTOR VALVE TESTING
| Knob Position | Function (Vacuum Hose Color/Port Number) | Condition | ||
|---|---|---|---|---|
| OFF | (1)Outside Air Shutoff (Orange/1) | Vacuum | ||
| Off | Partial Heat/Defrost (Blue/3) | Vacuum | ||
| Off | Full Heat/Defrost (Yellow/2) | Vacuum | ||
| Off | Vent/Heat (Red/4) | No Vacuum | ||
| Off | Source (White/5) | Vacuum | ||
| VENT | (1)Outside Air Shutoff (Orange/1) | No Vacuum | ||
| Vent | Partial Heat/Defrost (Blue/3) | No Vacuum | ||
| Vent | Full Heat/Defrost (Yellow/2) | No Vacuum | ||
| Vent | Vent/Heat (Red/4) | Vacuum | ||
| Vent | Source (White/5) | Vacuum | ||
| FLR | (1)Outside Air Shutoff (Orange/1) | No Vacuum | ||
| Heat | Partial Heat/Defrost (Blue/3) | Vacuum | ||
| Heat | Full Heat/Defrost (Yellow/2) | Vacuum | ||
| Heat | Vent/Heat (Red/4) | No Vacuum | ||
| Heat | Source (White/5) | Vacuum | ||
| MIX | (1)Outside Air Shutoff (Orange/1) | No Vacuum | ||
| Mix | Partial Heat/Defrost (Blue/3) | Vacuum | ||
| Mix | Full Heat/Defrost (Yellow/2) | No Vacuum | ||
| Mix | Vent/Heat (Red/4) | No Vacuum | ||
| Mix | Source (White/5) | Vacuum | ||
| Defrost | (1)Outside Air Shutoff (Orange/1) | No Vacuum | ||
| Defrost | Partial Heat/Defrost (Blue/3) | No Vacuum | ||
| Defrost | Full Heat/Defrost (Yellow/2) | No Vacuum | ||
| Defrost | Vent/Heat (Red/4) | No Vacuum | ||
| Defrost | Source (White/5) | Vacuum | ||
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