CAB GP 1566527 - Caterpillar

Load Check Switch
Illustration 1 g00726667
Load check switchThe load check switch signals to the ECM to activate the load check relay. If the engine is dead or there is no hydraulic pressure, the implements can be lowered by activating the load check switch. When the input to the load check (connector contact 14) of the ECM is closed to + battery voltage, the ECM activates the output of the load check relay (connector contact 37). The load check relay energizes the solenoids for the load check.Ride Control Switch
Illustration 2 g00726666
Ride Control SwitchThe ride control switch signals the mode that is selected by the operator to the ECM. The ride control switch has two input connections to the control: input 1 at connector contact 13 and input 3 at connector contact 14. When the operator selects AUTO mode, input 1 is open and input 3 is closed to the +battery. When the ON mode is selected, input 1 is closed to the +battery and input 3 is open. When OFF is selected, input 1 and input 3 are open.
Table 1
Status of the Ride Control Switch    
Mode     Switch Position     Input 1
Contact 13     Input 3
Contact 14    
ON     Up     +Battery     Open    
OFF     Center     Open     Open    
AUTO     Down     Open     +Battery    Note: A double-pole single-throw switch is used for diagnostic purposes. If the two poles are ever tied to + battery voltage, the control knows that a circuit failure is present. This fault is then shown on the diagnostic indicator. Refer to Systems Operation, "Diagnostic Operation".Primary Steering Flow Switch
During normal operation, the primary steering pressure switch connects the control input to ground. The switch opens when the flow in the primary steering is inadequate. The open switch signals the ECM to activate the secondary steering system.Speed Range Switch
The speed range switch is used to place the machine into either the high speed range or the low speed range. The creeper control is used on some machines to control the engine speed. When the speed input of the ECM is open, the ECM operates the machine in the high speed range. The speed input is closed to ground when the speed switch is in the low speed position.