Moturo Voltage Regulator Rectifier for Harley Davidson Big Twin 7451988

Moturo Voltage Regulator Rectifier for Harley Davidson Big Twin 89-99

The Moturo voltage regulator rectifier for your Harley Davidson Big Twin 89-99 — the component that keeps your vehicle's voltage stable over the years and protects the battery. Design and connections correspond to original 74519-88, ready for installation.

The regulator converts the alternating current (AC) from the alternator into the 12-volt direct current (DC) used in the electrical system and keeps it within the defined tolerance range. This ensures the battery charges reliably and prevents light bulbs from burning out.

Construction and performance correspond to the original 74519-88, and the connections match the factory layout. The fit and mounting points follow the design of the Big Twin Evo, tested on FXDL, FXDWG, FXSTSB, and FXDS-CON models from the 1989 to 1999 production period.

Replacement takes about half an hour with a socket wrench set and new connector plugs.

Voltage regulator for your Big Twin, made by Moturo.

Performance · Material · Specs

• Converts AC from the alternator into stable 12V DC for the electrical system
• Construction and performance correspond to original 74519-88
• Keeps onboard voltage within the defined tolerance range, charges the battery reliably
• Tested on FXDL, FXDWG, FXSTSB, and FXDS-CON (Big Twin Evo, model years 1989 to 1999)

Important notes – please read

Original replacement part design, no separate ABE (general operating permit) required. Check plug configuration and polarity against the old unit before connecting. Incompatible with Big Twins prior to 1989 and the Sportster platform.

Tools & Time required

• Socket wrench set for mounting nuts
• Multimeter for checking the vehicle voltage
• About half an hour for an experienced mechanic

Scope of delivery

1 × voltage regulator/rectifier (ready to connect). Not included: connector plugs, mounting hardware, tools, thermal paste.

Frequently Asked Questions

Does the regulator also fit Sportsters?
No, the alternator layout and mount are different.

Do I need an inspection/registration by the TÜV?
No. Original replacement part design in OE geometry.

How do I know if my old regulator is defective?
Measure the onboard voltage with the engine warm and at medium RPM — it should be between 13.5 and 14.5 volts.