41chevy 74 #1 Posted August 8, 2022 What causes my 1976 b 80 amp gauge to bounce wildly, reads nothing? Share this post Link to post Share on other sites
Pullstart 62,905 #2 Posted August 8, 2022 Amp meters on these old tractors aren’t much good for anything. They are better off removed and required a bit for a volt meter. If they fail, they wreak havoc in your wiring harness… like letting the magic smoke out. See example: magic smoke 1 Share this post Link to post Share on other sites
squonk 41,145 #3 Posted August 8, 2022 (edited) I know I'm in the minority on this but I prefer an ammeter. Unless you buy a good volt meter they are notoriously inaccurate. You can be tooling along reading 12 volts and it's actually 15 volts cooking your battery. Or reading 12,5 and it's actually just 12 and not charging at all. An ammeter showing a constant+ charging rate indicates your system is working and you either have a bad battery or a lot of music, lights and gumball machines running. If it shows a constant - charging rate your system is not working or you have too many lights, music or gumball machines running. If you're worried about the ammeter shorting out and burning all the wires up, put a fuse on it. Edited August 8, 2022 by squonk 2 Share this post Link to post Share on other sites
Pullstart 62,905 #4 Posted August 8, 2022 12 minutes ago, squonk said: put a fuse on it Share this post Link to post Share on other sites
953 nut 55,291 #5 Posted August 8, 2022 8 hours ago, 41chevy said: What causes my 1976 b 80 amp gauge to bounce wildly, reads nothing? Old age! The amp meter has two opposing springs and an electrical coil that will attract or repel a magnet depending on the current flowing through the coil. Springs get weak, moving parts get rusty; just old age setting in! I know, I resemble that remark! 4 1 2 Share this post Link to post Share on other sites
oldlineman 1,481 #6 Posted August 8, 2022 I'm with you sir! Share this post Link to post Share on other sites
