Tech Info: Should a fuse be installed on the battery positive to the alternator?

Should a fuse be installed on the hot to the alternator?


Good afternoon, I saw your YouTube video reference for the Big 4 wire upgrade after reading through 72 pages of S10 forum looking for the answer. The best answer was a good review on the AlternatorMan who's kind enough to post his phone number in the video title. I will be buying a Remy 91653 and a 96" serpentine belt to complete my alternator upgrade (maybe a new tensioner, or perhaps I'll downsize the idler to 70mm to match the tensioner instead of the longer belt). My question today: After doing the Big 4 upgrade (battery + to alt, alt case to engine, engine to body/chassis, and chassis to battery - ) should a fuse be installed on the hot to the alternator? If so, what size would be recommended for the Remy AD244 alternator? Thanks for your time.


Yes, you should put a fuse as close to the battery positive as possible. Since fuses restrict current flow, the fuse rating should be about 20% over the output rating of the alternator. If you have a 200A alternator, use a 240A fuse.