BCM Community

Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: BLOTZ TRUCK REPAIR on January 10, 2012, 07:26:59 AM

Title: 24 volt charging system
Post by: BLOTZ TRUCK REPAIR on January 10, 2012, 07:26:59 AM
I'm working on a 1982 MC9  got a gear driven rebilt 24 v 300 amp alt.new  3 post adj reg, and its over charging up to 36v its rpm sentived and less than 8vots on the fild wire reg turned all the way down. talked to DELCO and MCI no help.
Title: Re: 24 volt charging system
Post by: Lin on January 10, 2012, 08:12:06 AM
You say that it is newly rebuilt.  Can you speak to the rebuilder about what to do to make everything right?
.
Title: Re: 24 volt charging system
Post by: Sean on January 10, 2012, 08:13:03 AM
Make certain the Battery Sense lead from the regulator is properly connected.  You could also check that wire for excess resistance.  A disconnected, high-ohm, or improperly connected sense lead could cause overvoltage at the alternator.  In particular, if the sense terminal gets connected erroneously to the Relay output from the alternator, it will try to take the alternator to full voltage immediately.

Measuring the voltage at the field terminal is unrevealing unless you first know what that reading would be under "normal" charging conditions.  The field terminal is very low resistance to ground (on P-type alternators).

-Sean
Title: Re: 24 volt charging system
Post by: BLOTZ TRUCK REPAIR on January 10, 2012, 09:07:48 AM
have dicconected rely and also ck batt with a hydrometer charges  25v at idle at 4-5v on field as rpm increases field voltage gos up to 7-8 v butt output go to 35v and i think normal field voltage is 8-15v so i dont know why it sis charging so much at 8 volts.
Title: Re: 24 volt charging system
Post by: Sean on January 10, 2012, 11:49:19 AM
What are the part numbers on the alternator and the regulator?

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)
Title: Re: 24 volt charging system
Post by: BLOTZ TRUCK REPAIR on January 11, 2012, 09:06:10 AM
I will have to get them