Harddrive Regulator - Black XL `1978-1981 OEM 74504-78 — Harley-Davidson Sportster 1000, 1000 Roadster (1978-1981)

Harddrive regulator in black for 1978-1981 XL Sportster, meeting or exceeding OEM specifications. Uses high-power SCR technology and sealed encapsulation to run cooler and handle heat stress more effectively than stock units.

Features

• Meets or exceeds OEM specifications
• High-power SCR (Silicon Controlled Rectifier) design
• Sealed, high-temperature encapsulation
• Surface-mount circuit board for efficient heat dissipation
• OEM-grade wiring harness

Specifications

• Brand: Harddrive
• Manufacturer Part #: H0478
• UPC: 191361170263
• Weight: 0.9342 lbs
• Country of Origin: China (Mainland)

Fitment

Fits 1978-1981 Harley-Davidson Sportster XL models using OEM regulator mount.

Frequently Asked Questions

Will this fit my 1982 or newer Sportster?

No — this part is specific to 1978-1981 XL Sportster. Newer models use different charging systems.

What's the advantage over the stock regulator?

Harddrive's SCR design and sealed encapsulation allow cooler operation and better heat handling than original equipment.

Is this a direct bolt-in replacement?

Yes — uses the same OEM wiring harness and mount points as the original 1978-1981 regulator.

Will this improve my charging performance?

It meets or exceeds OEM output specs, ensuring reliable charging without the heat buildup of aged stock units.