Volvo 240/740/760/780/940/960 1990-1998

Throttle Switch

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OPERATION



See Figure 1



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Fig. Fig. 1: Internal components of the throttle switch

The throttle switch informs the fuel system and ignition system control units whether the throttle valve is closed or fully opened. The throttle switch is equipped with micro-switches for idling and full load running.

TESTING



See Figure 2

  1. Unplug the switch connector and connect an ohmmeter to the switch terminals. The center terminal is common, terminal No. 1 is the idle switch, terminal No. 3 is the full load switch.
  2.  
  3. The idle switch should be closed when the throttle is closed. Any movement of the throttle lever will open the switch just before the throttle plate actually opens. Operate the switch by hand, if necessary, to determine a faulty switch or faulty adjustment.
  4.  
  5. Connect the ohmmeter to the full load switch. The switch should close when the throttle lever is 70 degrees off idle, about 1 / 3 of full stroke.
  6.  
  7. If the switches are good but do not operate at the proper throttle angles, check the throttle cable adjustment.
  8.  



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Fig. Fig. 2: Throttle switch connector terminal identification

REMOVAL & INSTALLATION



  1. Disconnect the negative battery cable.
  2.  
  3. Remove any components necessary to access the sensor.
  4.  
  5. Remove the connector from the switch.
  6.  
  7. Remove the mounting screws from the sensor and remove the switch.
  8.  

To install:
  1. Install the switch onto the throttle plate shaft.
  2.  

The throttle plate shaft is designed to fit a specific way on the switch, note the position of the shaft before tightening the bolts.

  1. Tighten the mounting screws.
  2.  
  3. Install the switch connector.
  4.  
  5. Install any components removed to access the switch.
  6.  
  7. Connect the negative battery cable.
  8.  

 
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