MERCURY BLACK BOX 339-7452A1

Black Box (Switchbox) Mercury 339-7452A1 for Engines from 20 to 35 hp

The black box or switchbox is the electronic control module responsible for managing the ignition and the operation of the electrical system in 2-cylinder Mercury and Mercruiser engines in the range of 20 to 35 hp. This part is critical for starting and regulating the engine, acting as an intermediary between the battery, the alternator and the engine's ignition systems.

It is a highly reliable component designed to withstand the extreme conditions of the marine environment, including saline humidity and constant vibrations. Its replacement is necessary when the engine has starting problems, fluctuations in electrical load or intermittent ignition failures.

Engine Compatibility

Mercury/MerCruiser

Equivalent Manufacturer Part Numbers

Additional Technical Information

This black box is compatible with multiple variants of the 339-7452A series from Mercury, Mariner and Mercruiser, as well as the equivalent Sierra reference 18-5777. The most modern substitute reference is the 7452A3, which maintains full compatibility with previous systems.

At Repuestos Marinos we specialize in ensuring that each part we supply is exactly the right one for your engine. The nautical does not allow compatibility errors, so we recommend prior verification if you have doubts.