Mike'sHorseBarn 2,998 #1 Posted July 10, 2020 I've had the starter generator rebuilt because it was in real bad shape, new voltage regulator, new switch, new solenoid. Everything electrical is new. I've been running wires to check to see if I had a bad ground and still can't get it to charge. What am I missing? Share this post Link to post Share on other sites
WHNJ701 4,165 #2 Posted July 10, 2020 did you polarize it? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,046 #3 Posted July 10, 2020 I recall SOI stating you do not need to polarize it. The START mode does it for you. Garry Share this post Link to post Share on other sites
Mike'sHorseBarn 2,998 #4 Posted July 10, 2020 1 hour ago, jabelman said: did you polarize it? No I didn't because I thought on starter generators you didn't have to, but it can't hurt to try. Share this post Link to post Share on other sites
ebinmaine 67,596 #5 Posted July 10, 2020 Have you separated the circuitry and bench tested the SG by itself? 6 hours ago, jabelman said: did you polarize it? IF SG is operating correctly, the first time you start it it should polarize itself. Share this post Link to post Share on other sites
squonk 41,150 #6 Posted July 10, 2020 Take it off and bring it back to the rebuild and have it tested again. The charge coil may not be working while the start winding does. You can be pulling your hair out trying to fix it. Make sure it's the wiring or regulator. Do you have the right regulator? I had an alternator rebuilt by a big shop and it wouldn't charge. I spent hours on it. Turned out they put the wrong regulator into the alternator. Share this post Link to post Share on other sites
WHNJ701 4,165 #7 Posted July 10, 2020 try it by installing a spare s/g? that should narrow it if the rebuilt one is ok 1 Share this post Link to post Share on other sites
ebinmaine 67,596 #8 Posted July 10, 2020 How are you determining that it isn't charging? I ask because I .... Ummmmm.... Well ya see.... I tested every circuit I could find and then some, only to figure out that the lamp in the charge indicator wasn't any good. Share this post Link to post Share on other sites
Mike'sHorseBarn 2,998 #9 Posted July 11, 2020 1 hour ago, squonk said: Take it off and bring it back to the rebuild and have it tested again. The charge coil may not be working while the start winding does. You can be pulling your hair out trying to fix it. Make sure it's the wiring or regulator. Do you have the right regulator? I had an alternator rebuilt by a big shop and it wouldn't charge. I spent hours on it. Turned out they put the wrong regulator into the alternator. Yea I have the right regulator, I'll pull it off and have the starter generator re tested. Share this post Link to post Share on other sites
Mike'sHorseBarn 2,998 #10 Posted July 11, 2020 46 minutes ago, ebinmaine said: How are you determining that it isn't charging? I ask because I .... Ummmmm.... Well ya see.... I tested every circuit I could find and then some, only to figure out that the lamp in the charge indicator wasn't any good. When I put my meter on the battery at wide open throttle I'm only getting 12.4 volts. 1 Share this post Link to post Share on other sites
gwest_ca-(File Mod) 11,046 #11 Posted July 11, 2020 From the 4-72 Kohler service manual From the B&S service manual Garry Share this post Link to post Share on other sites
prondzy 3,881 #12 Posted July 11, 2020 15 hours ago, Mike'sHorseBarn said: When I put my meter on the battery at wide open throttle I'm only getting 12.4 volts. If your getting 12.4 v reading at WOT then the SG is charging. The igntion system is drawing off the battery and would result in a lesser volt reading. Is your engine running at 3600rpm or manufacturers spec for WOT? Is your SG belt slipping on the pullies? Share this post Link to post Share on other sites
Rob R 966 #13 Posted July 11, 2020 I always take the generator and the regulator to the rebuild shop and make sure they match them on a rebuild ..... never had and issue since doing that. Share this post Link to post Share on other sites
squonk 41,150 #14 Posted July 11, 2020 (edited) At 12.4 volts a Battery is approx 60% charged. You want at least 12.7 . I know splitting hairs here but I would think you need at least 13 volts running. What is the battery voltage with the engine off? See what the difference is between the two. Is the battery new also? If not it way be sucking so much current it's bringing the charge voltage down. As the charge current goes down, charge voltage goes up. It would be nice if you had an ammeter. Edited July 11, 2020 by squonk 1 Share this post Link to post Share on other sites
WHNJ701 4,165 #15 Posted July 11, 2020 I was told a s/g works more like maintainer, not a battery charger, you need a good fully charged battery for it to work correctly. Share this post Link to post Share on other sites
Mike'sHorseBarn 2,998 #16 Posted July 12, 2020 You guys have given me a couple things to check and if thay doesn't work, I have a few days off work in a couple weeks to run to run to the alternator shop where I take my stuff and see what they say. 1 Share this post Link to post Share on other sites
