41chevy 74 #1 Posted September 13, 2022 I’m thinking about putting a fuse in the amp meter line on my b 80, which line and what size fuse should I use? Thx Share this post Link to post Share on other sites
953 nut 51,628 #2 Posted September 13, 2022 The typical wiring on the B and C series has a 25 amp fuse installed in the red wire coming from the battery side of the solenoid to the ammeter. 1 Share this post Link to post Share on other sites
8ntruck 6,363 #3 Posted September 13, 2022 If you have a 15 amp alternator on yor engine, a fuse would need to be at least 15 amps. Not quite sure why you would want a fuse in line with your amp meter. If it blew, it would leave you running on your battery. Opinion here from a retired mechanical engineer with just enough electrical knowledge to be dangerous........ 3 2 Share this post Link to post Share on other sites
953 nut 51,628 #4 Posted September 13, 2022 @8ntruck, FYI, the 15 amp charging system is nominal and can exceed that value quite easily. I think the fuse protection @41chevy was seeking was going from the battery to the ignition switch wiring. 9 minutes ago, 8ntruck said: Opinion here from a retired mechanical engineer with just enough electrical knowledge to be dangerous...... I am a former electrician and know just enough about mechanical engineering to be dangerous so we are a pair. 2 2 Share this post Link to post Share on other sites
8ntruck 6,363 #5 Posted September 13, 2022 I do know that electrical things will work until the magic smoke gets released! 1 2 Share this post Link to post Share on other sites
pfrederi 17,145 #6 Posted September 13, 2022 Older WHs didn't have any fuses and most of them didn't catch fire... 3 Share this post Link to post Share on other sites
41chevy 74 #7 Posted September 14, 2022 Thanks for the reply guys, my concern was a wire fire. I go with what Paul said and forget about it. 3 Share this post Link to post Share on other sites
Achto 26,545 #8 Posted September 14, 2022 (edited) When I restore a tractor I always put a 30amp fuse in the wire that provides power from the battery to the ignition switch. If there is an amp meter the fuse is installed between the battery & the amp meter. I figure that it is better to blow a fuse than take the chance of burning up the wiring. I use a spade type in line fuse with a sealed holder. Edited September 14, 2022 by Achto 3 1 Share this post Link to post Share on other sites
squonk 38,902 #9 Posted September 14, 2022 13 hours ago, 8ntruck said: If you have a 15 amp alternator on yor engine, a fuse would need to be at least 15 amps. Not quite sure why you would want a fuse in line with your amp meter. If it blew, it would leave you running on your battery. Opinion here from a retired mechanical engineer with just enough electrical knowledge to be dangerous........ If you put the fuse inline with the ammeter and it blew you would kill power to the ignition switch and the engine would shut off on a battery ignition model. 2 1 Share this post Link to post Share on other sites
953 nut 51,628 #10 Posted September 14, 2022 14 minutes ago, squonk said: If you put the fuse inline with the ammeter and it blew you would kill power to the ignition switch and the engine would shut off on a battery ignition model. True, but the magic smoke would not escape the wires! 13 hours ago, 8ntruck said: I do know that electrical things will work until the magic smoke gets released! 1 Share this post Link to post Share on other sites
squonk 38,902 #11 Posted September 14, 2022 5 minutes ago, 953 nut said: True, but the magic smoke would not escape the wires! If you put the fuse right off the solenoid wire that feeds the ammeter the wires are protected. 1 Share this post Link to post Share on other sites
953 nut 51,628 #12 Posted September 14, 2022 13 hours ago, 953 nut said: The typical wiring on the B and C series has a 25 amp fuse installed in the red wire coming from the battery side of the solenoid to the ammeter. Is there an echo in here? 9 minutes ago, squonk said: If you put the fuse right off the solenoid wire that feeds the ammeter the wires are protected. 1 Share this post Link to post Share on other sites
squonk 38,902 #13 Posted September 14, 2022 Hellooo!!!!! 1 1 Share this post Link to post Share on other sites
ri702bill 7,313 #14 Posted September 14, 2022 (edited) 14 hours ago, pfrederi said: Older WHs didn't have any fuses and most of them didn't catch fire... Evidently, Dad's 702 is not one of them - had the steering wheel shaft abrade thru the 50 year old OE wiring about 10 years ago - lost the S/G voltage regulator in the process, along with the toastacated wiring. I have added 25 Amp fuses in weather proof holders to both the C81 and the 854 8 speed. just because.... Edited September 14, 2022 by ri702bill 2 2 Share this post Link to post Share on other sites
Heatingman 941 #15 Posted September 26, 2022 On 9/13/2022 at 5:58 PM, 8ntruck said: I do know that electrical things will work until the magic smoke gets released! Thats when the engineering starts. mmmm…how to get that smoke back in… Share this post Link to post Share on other sites
