Jun 262017
 

1970 Pontiac FirebirdSelecting an alternator

I recently add several electrical components to the engine and chassis.
Before selecting an alternator to handle the extra loads, I’ve been advised to compile a list of units and amp draws.
The add-ons list this info in their included literature, but I’m unable to find amp draws for the OEM units like: fan blower, headlights, ignition, radio etc.
Where I can I get this info?


Just use the max amp draw for that circuit. For example, the radio has a 5 amp fuse. even though this is the max amperage you could use it and be safe. Headlights use a 20 amp fuse. 30 amp for the blower. I would think just go for the largest available and you should be good. I am sure the 100 amp alternator would be fine but if you also have a hopped up stereo you may want to opt for the 130 amp alternator. Might as well through in an extra large battery as well.

Alternator Precautions

To prevent serious damage to the alternator and the rest of the charging system, the following precautions must be observed:

  • When installing a battery, make sure that the positive cable is connected to the positive terminal and the negative to the negative.
  • When jump-starting the car with another battery, make sure that like terminals are connected. This also applies when using a battery charger.
  • Never operate the alternator with the battery disconnected or otherwise on an uncontrolled open circuit. Double-check to ensure that all connections are tight.
  • Do not short across or ground any alternator or regulator terminals.
  • Don’t try to polarize the alternator.
  • Do not apply full battery voltage to the field (brown) connector.
  • Always disconnect the negative battery cable before disconnecting the alternator lead.

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