Wednesday, August 21, 2013

Bosch Alternator Regulators 1963-74 Models


  • Alfa Romeo
  • Audi
  • BMW
  • Cabpri
  • Fiat
  • Mercedes-Benz
  • Opel
  • Porsche
  • Saab
  • Volkswagen
  • Volvo
Bosch alternator regulators are two contact, single field units. The field coil of the alternator is grounded and voltage contacts of the regulator are in series with the field

Install a battery post adapter at the positive post of the battery. Connect voltmeter across the battery. Connect a tachometer to ignition system. Make sure all electrical accessories are turned off. Start engine with battery post adapter switch closed; open switch as soon as engine is started. With engine speed at 2500 RPM, load system with a 1/4 ohm resistance. After voltage reading stabilizes, any reading between 13.5 and 14.8 volts is satisfactory

If voltage reading is out of limits, remove regulator cover and adjust voltage regulator armature spring tension to obtain a middle reading of 14.0 volts. If reading fluctuates, voltage contacts are dirty. Replace regulator cover and recheck voltage setting. A steady voltage reading between 13.5 and 14.5 volts indicates regulator is in good condition.