Toyota Corolla 1970-1987 Repair Guide

Regulator

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All 1970-79 models are equipped with a separate, adjustable regulator. All 1980 and later models are either equipped with an external, adjustable regulator (like the earlier vehicles) or a transistorized regulator which is attached to the brush assembly on the side of the alternator housing. If faulty, the internal regulator must be replaced; there are no adjustments which can be made.

REMOVAL & INSTALLATION



External (Separate From Alternator)
  1. Disconnect the negative battery cable.
  2.  
  3. Disengage the wiring harness connector at the back of the regulator.
  4.  
  5. Remove the regulator mounting bolts.
  6.  
  7. Remove the regulator.
  8.  
  9. Installation is in the reverse order of removal.
  10.  

IC (Mounted In Alternator)
  1. Remove the alternator as detailed earlier in this section.
  2.  
  3. Remove the two screws on the back of the alternator housing, then remove the regulator end cover.
  4.  
  5. Underneath the end cover there are three terminal screws, remove them.
  6.  
  7. Remove the two regulator mounting screws, then remove the regulator.
  8.  
  9. Using a suitable tool, carefully pry out the plastic housing and the rubber seal around the regulator terminals.
  10.  
  11. Installation is in the reverse order of removal.
  12.  

ADJUSTMENT



Only regulators which are separate from the alternator are adjustable. Internally mounted IC regulators are NOT adjustable

Voltage
  1. Connect a voltmeter to the battery terminals. Negative (black) lead to the negative (-) terminal; positive (red) lead to positive (+) terminal.
  2.  
  3. Start the engine and gradually increase its speed to about 1,500 rpm.
  4.  
  5. At this speed, the voltage reading should fall within the range specified in the alternator and regulator specifications chart found later in this section.
  6.  
  7. If the voltage does not fall within the specifications, remove the cover from the regulator and adjust it by bending the adjusting arm.
  8.  
  9. Repeat Steps 2 and 3. If the voltage cannot be brought to specification, proceed with the mechanical adjustments found in this section.
  10.  

Mechanical

Perform the voltage adjustment outlined earlier in this section, before beginning the mechanical adjustments

FIELD RELAY

See Figure 1

  1. Remove the cover from the regulator assembly.
  2.  
  3. Use a feeler gauge to check the amount that the contact spring is deflected while the armature is being depressed.
  4.  
  5. If the measurement is not within specifications (refer to the alternator and regulator specifications chart found in this section), adjust the regulator by bending the point holder P2 (please see the illustration).
  6.  
  7. Check the point gap with a feeler gauge against the specifications in the chart.
  8.  
  9. Adjust the point gap, as required, by bending the point holder P1 (see the illustration).
  10.  
  11. Clean off the points with emery cloth if they are dirty and wash them with solvent.
  12.  

VOLTAGE REGULATOR

See Figure 2

  1. Use a feeler gauge to measure the air (armature) gap. If it is not within the specifications (refer to the alternator and regulator specifications chart), adjust it by bending the low speed point holder (please see the illustration).
  2.  
  3. Check the point gap with a feeler gauge. If it is not within specifications, adjust it by bending the high speed point holder (please see the illustration). Clean the points with emery cloth and wash them off with solvent.
  4.  
  5. Check the amount of contact spring deflection while depressing the armature. The specification should be the same as that for the contact spring on the field relay. If the amount of deflection is not within specification, replace, do not adjust, the voltage regulator. Go back and perform the steps outlined under Voltage Adjustment. If the voltage cannot be brought within specifications, replace the voltage regulator. If the voltage still fails to come within specifications, the alternator is probably defective and should be replaced.
  6.  



Click image to see an enlarged view

Fig. Fig. 1: Field relay adjustment components



Click image to see an enlarged view

Fig. Fig. 2: Voltage regulator adjustment components

 
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