GM Chevy Mid-Size Cars 1964-1988 Repair Guide

Neutral Safety/Back-Up Switch

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REPLACEMENT



See Figure 1

For automatic transmissions both the neutral safety/back-up switches are combined into a single unit. The switch prevents the engine from being started in any transmission position except NEUTRAL or PARK. The switch is located on the upper side of the steering column under the instrument panel on column shift cars and inside the shift console on floor shift models.

Models Through 1981
  1. Disconnect the negative battery cable.
  2.  
  3. Remove the console for access on floor shift models.
  4.  
  5. Disengage the electrical connectors.
  6.  
  7. Remove the neutral switch.
  8.  

To install:
  1. Place 1964-70 column shift lever models in DRIVE, and 1971 and later models in NEUTRAL. Locate the lever tang against the transmission selector plate on column shift models. Place 1964 through early 1972 floor shift models in DRIVE, and mid-1972 and later models in PARK.
  2.  
  3. Align the slot in the contact support with the hole in the switch. Insert a 3 / 32 in. pin in place. The switch is now aligned in the DRIVE position.
  4.  

For 1973-81 applications, replacement neutral safety switches have a shear-pin installed to aid in proper switch alignment so that insertion of a pin is unnecessary. After installation, moving the shift lever from NEUTRAL shears the pin.

  1. Place the contact support drive slot over the drive tang. Install the switch mounting screws.
  2.  
  3. Remove the aligning pin. Engage the electrical wiring and, if applicable, install the console.
  4.  
  5. Connect the negative battery cable.
  6.  
  7. Set the parking brake and hold your foot on the brake pedal. Check to see that the engine will start only in PARK or NEUTRAL.
  8.  



Click image to see an enlarged view

Fig. Fig. 1: Examples of common neutral safety switch installation-floor and column mounted shifters

1982 and Later
  1. Disconnect the negative battery cable.
  2.  
  3. Disengage the wiring harness from the switch.
  4.  
  5. Remove the retaining screws and switch assembly.
  6.  

To install:
  1. Position the gear selector in NEUTRAL.
  2.  
  3. Align the actuator on the switch with a hole in the switch tube.
  4.  
  5. Position the rearward portion of the switch (connector side) to fit into the cutout in the lower jacket.
  6.  
  7. Push down on the front of the switch. The two tangs on the housing back will snap into place in rectangular holes in the jacket.
  8.  
  9. Adjust the switch by moving the gear selector to PARK. The main housing and the housing back should ratchet, providing proper switch adjustment.
  10.  
  11. Make sure the switch is properly secured, then engage the wiring harness.
  12.  
  13. Connect the negative battery cable, then verify that the engine will only start in NEUTRAL or PARK. Be sure to firmly apply the brake when checking switch operation.
  14.  

SWITCH ADJUSTMENT



See Figure 2

Models Through 1981
  1. Place shift lever in NEUTRAL.
  2.  
  3. If necessary, remove the center console for access to the switch.
  4.  
  5. Move the switch until you can insert a 0.0938 in. (2.381mm) gauge pin through the hole in the switch and through the alignment hole.
  6.  
  7. Loosen the switch securing screws and move the switch, as necessary to insert the pin.
  8.  
  9. Tighten the screws and remove the pin.
  10.  
  11. Step on the brake pedal and check to see that the engine will only start in NEUTRAL or PARK.
  12.  
  13. If removed for access, install the center console assembly.
  14.  



Click image to see an enlarged view

Fig. Fig. 2: Neutral safety switch adjustment

1982 and Later
  1. With the switch installed, move the housing all the way toward LOW.
  2.  
  3. Adjust the switch by moving the gear selector to PARK. The main housing and the housing back should ratchet, providing proper switch adjustment.
  4.  

 
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