msarnold1990 Posted April 5, 2021 Report Share Posted April 5, 2021 Hi All, I installed a restored generator and seem to be having some issues. I drove all over yesterday and it seemed fine. However at night when I was using my lights, it was drawing a lot of power and not getting back to zero on the ammeter. It currently sits right below zero when I am idling and does not move at all when I rev the engine in idle. I believe I polarized the generator correctly, using a wire to touch the Bat terminal to the Arm terminal briefly and saw a few sparks. Am I missing something? Could my battery be going? Quote Link to comment Share on other sites More sharing options...
ccudahy Posted April 5, 2021 Report Share Posted April 5, 2021 (edited) My Plymouth was doing very similar thing. Is your voltage regulator a new replacement or original? I just had my generator rebuilt and found out from the machinist who did the work that the replacement regulators are not adjust properly out of the box. The output voltage might be on the low side and/or the the "kick in and out" amperage is set too high/low respectively. The gaps on the points in the voltage regulator need to be adjusted to corrects these issues. It also need to be at operating temperature and the metal cover need to be on to get accurate measurements. This happen to be my case. The output voltage when cold was 7.8 volts, when warm was only 6.6-6.8 volts and the generator did not "kicked in" until the draws was over 12 amps. He adjusted it so the output voltage is now around 7.6 volts and "kicks in" around 1.0-2.0 amps (I think can't quite remember the new amperage setting). He even had it set up on the test stand with an NOS ammeter and load tester to show that everything works good. Edited April 5, 2021 by ccudahy 1 Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted April 5, 2021 Report Share Posted April 5, 2021 Looks like you a 20A draw when lights are on but what does it show when lights are off? There is easy procedure to find out if it's a generator or regulator problem. Quote Link to comment Share on other sites More sharing options...
msarnold1990 Posted April 5, 2021 Author Report Share Posted April 5, 2021 Lights off it still draws slightly negative. Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted April 5, 2021 Report Share Posted April 5, 2021 Not good. Try this. Turn of lights, radio and other ACC. Disconnect Field terminal from generator. Let engine idle. Have someone watch the amp gauge. Connect field terminal to ground and rev up slowly. Gauge should go to + side. A better way is to measure the A terminal while revving. Will show up to 40volts ! Do not rev it for too long. If gauge moves to plus, your generator is ok. I f no movement, generator is bad Quote Link to comment Share on other sites More sharing options...
msarnold1990 Posted April 6, 2021 Author Report Share Posted April 6, 2021 19 hours ago, chrysler1941 said: Not good. Try this. Turn of lights, radio and other ACC. Disconnect Field terminal from generator. Let engine idle. Have someone watch the amp gauge. Connect field terminal to ground and rev up slowly. Gauge should go to + side. A better way is to measure the A terminal while revving. Will show up to 40volts ! Do not rev it for too long. If gauge moves to plus, your generator is ok. I f no movement, generator is bad Sorry for so many questions. I'm brand new to all of this. Which terminal is the field terminal on the generator? And it's okay to remove it while the generator is running? And by "connecting the field terminal to ground" what does that mean? Taking that field terminal and grounding it on the generator with a clamp?" Quote Link to comment Share on other sites More sharing options...
greg g Posted April 6, 2021 Report Share Posted April 6, 2021 The smaller diameter terminal is the field. Make a jumper wire. Do a 6ft length of 12 gauge wire. Put an insulated alligator clips on the ends. Hook one clamp to the Gen terminal and the other end to anywhere on the block or to the ground battery cable. In this case it bypasses the cutout circuit in the VR causing the Gen to produce at Max output. The jumper makes a handy thing in your tool box for checking grounds, bypassing suspect switches or circuits. The all purpose tool for trouble shooting electrical Gremlins. Quote Link to comment Share on other sites More sharing options...
msarnold1990 Posted April 6, 2021 Author Report Share Posted April 6, 2021 Gotcha, that makes sense. I'll try that. Thanks! Quote Link to comment Share on other sites More sharing options...
msarnold1990 Posted April 6, 2021 Author Report Share Posted April 6, 2021 The test did not work. But I used a voltmeter on the generator while running. It seems to be putting out 1.7 Volts, which is definitely out of range. My guess is the voltage regulator needs adjustment. Quote Link to comment Share on other sites More sharing options...
greg g Posted April 7, 2021 Report Share Posted April 7, 2021 Check the generator brushes. The test takes the regulator out of the loop, meaning the fault is most likely in the gen. Quote Link to comment Share on other sites More sharing options...
Sam Buchanan Posted April 7, 2021 Report Share Posted April 7, 2021 There is a very reliable alternative to messing with the old generator and regulator: https://www.ebay.com/str/HowardEnt?_trksid=p2047675.l2563 2 Quote Link to comment Share on other sites More sharing options...
DJK Posted April 7, 2021 Report Share Posted April 7, 2021 Love my 6v pos ground alternator from Bill Howard Enterprises!!! Quote Link to comment Share on other sites More sharing options...
chrysler1941 Posted April 7, 2021 Report Share Posted April 7, 2021 14 hours ago, msarnold1990 said: The test did not work. But I used a voltmeter on the generator while running. It seems to be putting out 1.7 Volts, which is definitely out of range. My guess is the voltage regulator needs adjustment. Try and test it again. This test method is over 100 years old. This time remove both wirings on generator. Ground Field terminal (small stud) and measure volts DC at A (the bigger stud) to ground. Quote Link to comment Share on other sites More sharing options...
msarnold1990 Posted April 7, 2021 Author Report Share Posted April 7, 2021 Ok I'll try that Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.