HOSE AS 4855084 - Caterpillar

Illustration 1 g01331641
"Air Conditioning Operator" Switch connections
The "Air Conditioning Operator" Switch supplies one switch to +battery input to the "Transmission/Chassis ECM". The ECM does not monitor the switch circuits that have one input for diagnostics.During normal operation, the ECM internal pull down voltage will hold the switch input circuit low until the +battery signal from the "HVAC Fan Selector" switch is passed through the switch contacts. The ECM detects the high +battery signal in the circuit and determines that the switch contacts are closed.Note: For a more detailed explanation of the operation of the air conditioning system, refer to Systems Operation, "Features" section of this manual.If the switch circuit is OPEN or the switch contacts have failed in the OFF state, the ECM will not detect that the switch contacts are closed and will not activate the air conditioning system. If the input circuit of the switch is shorted to frame ground or to another ground source, the "HVAC" fuse will open when the switch is moved to the AC ON position.If the contacts of the switch fail in the AC ON state, the ECM will not detect the low in the circuit to indicate that the contacts are open. When this occurs, the air condition system will be active at all times.Some conditions that can cause the AC operator switch input circuit to fail are listed.
The HVAC fuse is open due to a short to ground in the switch input circuit or other factors.
The switch has failed.
The input circuit of the switch is open or the switch has a poor connection in