Testing the generator

[GC Mayes]

guys my CA is running great. The AMP meter stays dead center on Zero. Any good way to check Generator output to see if it is working correctly or if the AMP meter maybe bad?

thanks in advance George

 

[John T]

Sure can, in Para 5 of my Troubleshooting Procedure you can determine if non charging is:

1) A genny versus a VR problem,,,,,,,
2) How to use the old ground the Field trick (to allow for max charge independant of any VR or light switch field grounding and control issues) to see if the genny then charges.
3) How to "Motor Test" to see if the genny is good

To answer your other concerns:

a) You can simply by pass shunt across an ammeter to see if the battery is then accepting a charge. If so its normal setting voltage of 12.6 (6.3 on a 6 volt) would rise to the 13 to 14 and over volt range (1/2 that on 6 volt) if connected to a good working charging system. i.e. just jump across a bad/open meter to see if she charges then.

b) Also an ammeter is a very low resistance 2 terminal in/out passive device, so an ohm meter across it should read very low ohms BUT IF ITS AN OPEN CIRCUIT (near infinity ohms) then its bad and charging current could NOT flow through it to get to and charge the battery even if all else is fine. PS some ammeters have seperate external shunts remember, the above is more for the total enclosed type meters.

c) If an ammeter works right and is wired right if you turn lights or ignition (unless a mag) on it should swing over to - discharge. Sometimes the neede just gets mechanically stuck/jammed. HOWEVER even if the needle was stuck so long as its NOT an open circuit the battery may still be charged even thought the needdle dont indicate such..Thats why one can still simply measure the battery voltage to see if it rises as RPM increases as it should IFFFFFFF the genny is working EVEN IF THE AMMEETR ISNT MOVING so long as its NOT an open circuit because then the charging current cant get to the battery. Its supposed to flow THROUGH the ammeter on its way to the battery so you can monitor it well DUH lol


No sense in me reinventing the wheel all over each time so work through my Troubleshooting Procedure to see whats the cause of non charging such as the genny itslef or the VR etc. If it or the above missed anything hope others can add to this.

Best wishes

http://www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=665110

John T
John Ts Troubleshooting Procedure