This voltage control box regulates generator output on Austin Healey models fitted with a 12-volt dynamo and external control box. It manages battery charging and electrical load to prevent overcharging or unstable voltage during normal driving.
Yes, if the car uses a generator and external control box.
Designed for Big Healey models using a 12-volt dynamo system and a separate voltage control box.
Not suitable for:
Mounting hardware and wiring are not included.
Installation is straightforward for vehicles retaining standard wiring. Generator output and cut-in settings should be checked after fitting. Minor adjustment or calibration may be required to suit individual generators and wiring condition.
Inspection of wiring, terminals, and earth connections is strongly recommended before installation.
Download Fitting Instructions (PDF)
This unit matches the original generator-controlled charging layout used on BN1–BJ7 models, making it a sensible choice for owners retaining a traditional electrical system rather than converting to an alternator.
BJ8 models use a different voltage control box specification. If the car is a BJ8 and retains a generator charging system, use the correct BJ8 control box instead.
View Austin Healey Voltage Control Box for BJ8
No. Alternator systems use internal or different external regulation and do not require this type of control box.
The vehicle’s electrical polarity must be checked before installation. Generator systems can be configured for positive or negative earth.
Charging voltage should be verified after installation. Some setups may need minor calibration depending on generator condition.
Yes. Poor earths, aged wiring, or corroded terminals can cause unstable charging regardless of control box condition.
