GM Full Size Vans 1967-1986 Repair Guide

Regulator

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REMOVAL & INSTALLATION



1967-72 Models

See Figure 1



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Fig. Fig. 1: Regulator voltage setting circuit for 1967-72 models

  1. Disconnect the ground cable from the battery.
  2.  
  3. Disconnect the wiring harness from the regulator.
  4.  
  5. Remove the mounting screws and remove the regulator.
  6.  
  7. Make sure that the regulator base gasket is in place before installation.
  8.  
  9. Clean the attaching area for proper grounding.
  10.  
  11. Install the regulator. Do not overtighten the mounting screws, as this will cancel the cushioning effect of the rubber grommets.
  12.  

1973 and Later Models

The regulator on these models is an integral part of the alternator. Alternator disassembly is required to replace it.

VOLTAGE ADJUSTMENT



1967-72 Models

The standard voltage regulator from 1967-72 is a conventional double contact unit, although an optional double contact unit, although an optional transistorized regulator was available. Voltage adjustment procedures are the same for both types except for the point of adjustment. The double contact adjusting screw is located under the cover and the transistorized regulator is adjusted externally after removing an allen screw from the adjustment hole.

  1. Insert a 0.25 ohm, 25 watt fixed resistor into the charging circuit at the horn relay junction block, between both leads and the terminal. Use a 0.50 ohm, 25 watt resistor for 1971-72.
  2.  
  3. Install a voltmeter as shown.
  4.  
  5. Warm the engine by running it for several minutes at 1,500 rpm or more.
  6.  
  7. Cycle the voltage regulator by disconnecting and reconnecting the regulator connector.
  8.  
  9. Read the voltage on the voltmeter. If it is between 13.5 and 15.2, the regulator does not need adjustment or replacement. If the voltage is not within these limits, leave the engine running at 1,500 rpm.
  10.  
  11. Disconnect the 4-terminal connector and remove the regulator cover (except on transistorized regulators). Reconnect the 4-terminal connector and adjust the voltage to between 14.2 and 14.6 volts by turning the adjusting screw while observing the voltmeter.
  12.  
  13. Disconnect the terminal, install the cover, then reconnect the terminal.
  14.  
  15. Continue running the engine at 1,500 rpm to re-establish the regulator internal temperature.
  16.  
  17. Cycle the regulator by disconnecting/reconnecting the regulator connector. Check the voltage. If the voltage is between 13.5 and 15.2, the regulator is good.
  18.  


WARNING
Always disconnect the regulator before removing or installing the cover in order to prevent damage by short circuiting.

1973 and Later Models

On 1973 and later models, the 10 SI Delcotron is used which is equipped with an integral regulator that cannot be adjusted.

 
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