Harddrive Chrome Regulator - Harley Sportster 1000 1978-1981
About Harddrive
Harddrive is the house performance and replacement line built for American V-twins, covering everything from engine hardware and electrical to controls, lighting and chassis parts. The range is aimed squarely at Harley-Davidson and Indian riders who want a direct-fit part without dealer pricing, and it spans decades of model years — from Evolution-era Softails to current Milwaukee-Eight baggers.
Keep your vintage Sportster's charging system running strong with this Harddrive chrome voltage regulator. Designed for 1978-1981 Harley-Davidson Sportster 1000 models, it delivers stable power to your battery and electrical components.
Why riders pick this
- Meets or exceeds OEM specifications for quality and fit
- High-power SCR technology for cooler, more efficient operation
- Sealed encapsulation protects against heat and moisture
- Surface-mount circuit board design minimizes thermal impedance
- OEM-grade wiring harness for a straightforward installation
This Harddrive regulator is engineered to meet or exceed OEM specifications, ensuring a reliable replacement for your aging factory unit. It features advanced SCR technology and sealed encapsulation, which work together to dissipate heat more effectively than older designs.
Cooler Operation, Longer Life
- High-power SCR (Silicon Controlled Rectifier) technology for cooler running
- Sealed, high-temperature encapsulation protects internal components
- Surface-mount circuit board minimizes thermal impedance
- OEM-grade wiring harness for a direct fit and reliable connections
Reliable Power for Your Classic V-Twin
A properly functioning voltage regulator is critical for maintaining battery health and preventing electrical issues on your Sportster. This Harddrive unit is built to withstand the demands of the road, providing consistent voltage regulation to keep your lights bright and your engine firing. It's an ideal upgrade for riders looking for enhanced reliability and performance from their classic Harley-Davidson.
Specifications
- Brand: Harddrive
- Manufacturer Part #: H0478C
- UPC: 191361170270
- OEM Reference: 74504-78
- Length: 4.68 in
- Width: 3.5 in
- Height: 1.68 in
- Weight: 0.8 lbs
- Country of Origin: China (Mainland)
Common questions
Will this regulator fit my 1982 Harley-Davidson Sportster?
No, this Harddrive regulator is specifically designed for 1978-1981 Harley-Davidson Sportster XL models. Later Sportsters utilize different charging systems and require a different part.
What is the main benefit of SCR technology in this regulator?
The high-power SCR (Silicon Controlled Rectifier) technology allows the regulator to run cooler and more reliably, especially in high-heat applications, which helps extend the life of your battery and other electrical components.
Is this a direct bolt-on replacement for the original part?
Yes, this Harddrive regulator is designed as a direct replacement for OEM part 74504-78, meaning it should install without major modifications on compatible Sportster models.
Ordering from Vtwinbikers
- Brand new, sourced through authorized US distribution — never used, never grey-market.
- Not sure it fits? Use Shop by Bike to filter by your year and model, or email us and we will confirm before you order.
- Harley-Davidson and Indian Motorcycle is all we do, so you are talking to people who ride what you ride.
| BRAND | Harddrive |
| TYPE | Electrical |
| SKU | 820-60149 |
| WEIGHT | 0.8 lb |
