Author	[Modern View]
Jeremy Miller 07-20-2012 20:22:19 166.181.3.142 Report to Moderator	The generator is not working on my gas 4020 with 12 volt system. With the wires disconnected is it normal to have continuity between the F terminal on the generator on the tractor frame? When I try to full field the generator by grounding the F terminal I get erractic voltage readings sometimes 24 volts sometimes just 2 or 3 volts. Not sure if generator is bad or not. Confused about the terminals showing ground through my meter. [Reply]   [No Email]
John T 07-21-2012 04:01:41 216.249.82.117 Report to Moderator	Re: John Deere 4020 Generator in reply to Jeremy Miller, 07-20-2012 20:22:19   QUESTION With the wires disconnected is it normal to have continuity between the F terminal on the generator on the tractor frame? ANSWER YES THATS NORMAL (would be bad if there wasnt) Id expect something like 3 to 6 or so ohms from FLD to the gennys case frame if the Field windings are good and continuous QUESTION When I try to full field the generator by grounding the F terminal I get erractic voltage readings sometimes 24 volts sometimes just 2 or 3 volts ANSWER Possible problems are the brushes are worn down too low or the hold down spring are stuck and arent keeping the brushes down tight or the commutator is all oiled n greasy or the insulator segments arent properly undercut or there may be a loose connection or a poor ground Run my Troubleshooting Procedure: Was the genny properly polarized BEFORE start up??? If not the VR may be damaged John T John T's Troubleshooting [Reply]  [No Email]
buickanddeere 07-20-2012 21:29:02 209.240.122.110 Report to Moderator	Re: John Deere 4020 Generator in reply to Jeremy Miller, 07-20-2012 20:22:19   Poor contact through the chassis, frame, generator body to the regulator? Is the battery installed + or - to chassis? Yes those Delco's are supposed go into charge mode when the F terminal is "grounded" to chassis. How is the brush length and spring tension? Armature out of round or high mica? An alternator conversion properly done on a new Generation does not look out of place. Higher the current rating the better. [Reply]  [No Email]