BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: tony on December 02, 2010, 04:58:11 AM

Title: polarize
Post by: tony on December 02, 2010, 04:58:11 AM
does anyone know how to polarize a generator to a regulator
Title: Re: polarize
Post by: Sean on December 02, 2010, 05:58:35 AM
The polarity of an alternator is determined by the diode packs.

If you have a negative-ground alternator and you want to make it positive-ground (or vice-versa), you need to change the diodes.  Generally that requires that the alternator manufacturer makes and sells a positive-ground (or negative-ground) diode pack for the unit.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Title: Re: polarize
Post by: robertglines1 on December 02, 2010, 06:08:20 AM
Generator: My 78 mci had a alternator. If you have a Generator ck how in a older car manual like in the 50"s. can"t remember the sequence but can remember doing it. is voltage regulator marked F  B  A  ?
Title: Re: polarize
Post by: Van on December 02, 2010, 06:38:43 AM
Not sure if this helps. On the older cars and Harleys with generators, you flash (touch) the field terminal to ground, check and double check, first to be sure this is your particular case, good luck!
Title: Re: polarize
Post by: Sean on December 02, 2010, 06:41:58 AM
OK, if it's really a "generator" meaning that it is straight DC with commutators and brushes, you just need to momentarily touch hot to "F" to change polarity, or momentarily short "A" and "F."

However, many so-called "generators" are actually alternators, and I don't think any 1980 MCI was fitted with a DC generator.  Specifically, Delco called the 50DN a "generator" for a long time even though it was an alternator and had diode packs.

FWIW.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Title: Re: polarize
Post by: rgrauto on December 02, 2010, 06:45:43 AM
Tony, I usually use a jumper wire hooked to the + - power to momentarily to touch the F-field  terminal,that usually does it. HTH Glen