Alternator voltage

[aa-1159]

Is there anyway to keep alternator excited at low rpm,
Car idles at 850,(12 volts or less) alternator won't excite until around 1000 rpm, (14.4), above 1000 rpm
73 Duster, 360, has serpentine set up,
Called manufacturer about pulley size, they said pulley made to spec of original pulley
Don't want to go to 1 wire setup

 

[Dana67Dart]

If you are worried about slight discharge at idle. No need to be. You loose 1% charge at idle but put 5% charge back in between stop lights.

Overall it's a net gain.

 

[Bewy]

Agree with this^^^^. If it still worries you, fit a smaller alt pulley.

 

[67Dart273]

Is there anyway to keep alternator excited at low rpm,
Car idles at 850,(12 volts or less) alternator won't excite until around 1000 rpm, (14.4), above 1000 rpm
73 Duster, 360, has serpentine set up,
Called manufacturer about pulley size, they said pulley made to spec of original pulley
Don't want to go to 1 wire setup

What kind of alternator? What kind of regulator? A "one wire" will not help and may very well hurt.

The newer tech alternators generally are better at lower RPM than the old "round back" Mopars. The newer Mopar "square back" which came out somewhere around 73 are better than the round backs.

Also what kind of load? AKA you have EFI, electric fans and water pump/ fuel pump?

 

[Dana67Dart]

alternator won't excite until around 1000 rpm, (14.4)

If you are looking at the alternators rating sheet remember that's alternator shaft rpm NOT engine rpm.

If you have a 6.5 inch crank pulley and a 2.5" alt pulley you have a ratio of 2.6 so 600 crank rpm results in 1560 alternator shaft rpm.

 

[Mattax]

I agree. measure the crank and alt pulley diameters. Then compare to the factory ratios.