[rotorwrench]

MikeK has a point about these types of 1-wire conversion alternator. On the GM/Delco 10si type alternators, the rectifier is changed to get the 6-volts needed and has a jumper to the regulator module and the brush holder stack. These alternators may be one wire now but they were never designed to be that. They have the plug with the 2-male spade terminals that were used in the original OEM installations for the alternator warning light and the system voltage sense. Model As and tractors don't use this stuff but that doesn't mean that they couldn't. It's just that it is not considered important by the producers of this equipment. If these two circuits were set up (making it a 3-wire system), it may help with the output of these type units. That voltage sense wire was pretty important to the way the internal regulator works. Since the regulator doesn't know what the battery voltage is, it just has to put out a constant default voltage for it to work.

The alternator has to be pulled apart and a conversion regulator set up purchased to supply the parts for replacement but it can be done by most DIY guys.