Uploaded June 2026 | Updated September 2026, 4 days ago
Kiley's 1967 Mustang Hardtop has its alternator on the driver's side and its battery on the passenger side — and about 12 feet of engine bay in between. Before we run a single inch of cable, we've got to get three things right: the wire gauge, the route, and the fuse. Get the gauge wrong and the alternator can't properly charge the battery across that distance. Skip the fuse and, well… my buddy Cam says it's all gonna burn to the ground anyway. We'd rather it didn't.
In this one we plan out the main battery cable for the charging system on Kiley's Mustang — mocking up the run with some cheap parts-store wire, measuring the full 12 feet, picking the right gauge for our 100-amp alternator, and speccing the MIDI fuse holder that keeps the whole works from becoming a campfire. There's already an American AutoWire harness on the car, so part of the battle's done. The rest is fit and fiddle, getting power from the alternator over to the starter solenoid on the inner fender.
In this episode:
• Why the alternator-to-battery run matters for proper charging, and what voltage drop does over distance
• Picking wire gauge based on your alternator's amperage and the length of the run
• Routing the cable the smart way — around the perimeter, not across the engine
• Crimped vs. soldered connections (fight us in the comments)
• The 125-amp MIDI fuse that keeps a short from torching your build
• Why you keep a spare fuse in the glovebox
The battery cables on this one are coming from Fast and Quiet — American-made, South Carolina folks like us, crimped ends and fine-strand welding wire. Most of our parts come from our friends at National Parts Depot. Links below.
— SUPPORT THE SHOP — Grab a shirt at our Fourth Wall store — "automotive dismantling and hoarding disorder," "needs classic cars," and more. Every shirt helps us pay our camera crew and editor and keep the lights on. Join us on Patreon: at the $10/month level you get monthly Zoom hangouts with me. Come kick the tires.
If this helped, give it a like, subscribe, and ring the bell so you don't miss the rest of the electrical series.
Be kind to each other. Love on each other. Treat each other nice. We'll see you next time on Autorestomod.
It’s not a Problem, It’s a Project!
Parts:
fastandquiet.com
Autorestomod Episode: 745
autorestomod-shop.fourthwall.com
Sponsors:
nationalpartsdepot.com
eatondetroitspring.com
Contact: Jford@autorestomod.com
Insta: @autorestomod
patreon.com/gasolinemedia.
#Autorestomod #1967Mustang #Restomod #ClassicCarRestoration #AutomotiveWiring
Kiley's 1967 Mustang Hardtop has its alternator on the driver's side and its battery on the passenger side — and about 12 feet of engine bay in between. Before we run a single inch of cable, we've got to get three things right: the wire gauge, the route, and the fuse. Get the gauge wrong and the alternator can't properly charge the battery across that distance. Skip the fuse and, well… my buddy Cam says it's all gonna burn to the ground anyway. We'd rather it didn't.
In this one we plan out the main battery cable for the charging system on Kiley's Mustang — mocking up the run with some cheap parts-store wire, measuring the full 12 feet, picking the right gauge for our 100-amp alternator, and speccing the MIDI fuse holder that keeps the whole works from becoming a campfire. There's already an American AutoWire harness on the car, so part of the battle's done. The rest is fit and fiddle, getting power from the alternator over to the starter solenoid on the inner fender.
In this episode:
• Why the alternator-to-battery run matters for proper charging, and what voltage drop does over distance
• Picking wire gauge based on your alternator's amperage and the length of the run
• Routing the cable the smart way — around the perimeter, not across the engine
• Crimped vs. soldered connections (fight us in the comments)
• The 125-amp MIDI fuse that keeps a short from torching your build
• Why you keep a spare fuse in the glovebox
The battery cables on this one are coming from Fast and Quiet — American-made, South Carolina folks like us, crimped ends and fine-strand welding wire. Most of our parts come from our friends at National Parts Depot. Links below.
— SUPPORT THE SHOP — Grab a shirt at our Fourth Wall store — "automotive dismantling and hoarding disorder," "needs classic cars," and more. Every shirt helps us pay our camera crew and editor and keep the lights on. Join us on Patreon: at the $10/month level you get monthly Zoom hangouts with me. Come kick the tires.
If this helped, give it a like, subscribe, and ring the bell so you don't miss the rest of the electrical series.
Be kind to each other. Love on each other. Treat each other nice. We'll see you next time on Autorestomod.
It’s not a Problem, It’s a Project!
Parts:
fastandquiet.com
Autorestomod Episode: 745
autorestomod-shop.fourthwall.com
Sponsors:
nationalpartsdepot.com
eatondetroitspring.com
Contact: Jford@autorestomod.com
Insta: @autorestomod
patreon.com/gasolinemedia.
#Autorestomod #1967Mustang #Restomod #ClassicCarRestoration #AutomotiveWiring
