18736A21 Mercury Voltage Regulator | Genuine Used Part

🔧 Product Description

Genuine Mercury Dual Voltage Regulator Kit - Part Number: 18736A21

A genuine Mercury voltage regulator reference used on V6 two-stroke outboard charging systems. This regulator is commonly associated with 40 amp six-cylinder Mercury / Mariner charging systems and cross-references with dual-regulator aftermarket kits for engines requiring four yellow wire stators.

⚙️ Key Features

• Genuine Mercury voltage regulator reference

• Correct Mercury part number 18736A21

• Related to earlier Mercury regulator references 18736A8 and 18736A11

• Used on V6 two-stroke Mercury / Mariner 135HP to 200HP charging systems where specified

• Charging-system component requiring exact stator wire configuration and parts-diagram confirmation

🔄 Supersession & Cross Reference

OEM Supersession Chain:

• 18736A21 current / later Mercury voltage regulator reference

• 18736A11 earlier related voltage regulator reference

• 18736A8 earlier related voltage regulator reference

OEM / Related Numbers:

• 18736A21

• 18736A20

• 18736A11

• 18736A8

• 194-1873

• 174-9610A18

• 194-8736K 1

• 194-5279R component regulator reference

• Related 40 amp six-cylinder regulator / rectifier charging-system family

Aftermarket / Verified Equivalents:

• CDI Electronics: 194-8736K 1

• CDI Electronics: 194-5279R component regulators

• WSM / aftermarket conversion family: 174-9610A18

• Aftermarket replacement reference: 194-1873

🚤 Compatibility

Commonly used on:

• Mercury / Mariner V6 two-stroke 40 amp charging systems using the 18736A21 regulator family

Typically suits:

• Engine models:

• Mercury 135HP V6 two-stroke 1989-1991 charging systems with 40 amp output and four yellow wire stator configuration

• Mercury 150HP V6 two-stroke 1989-1991 charging systems with 40 amp output and four yellow wire stator configuration

• Mercury 175HP V6 two-stroke 1989-1991 charging systems with 40 amp output and four yellow wire stator configuration

• Mercury 200HP V6 two-stroke 1989-1991 charging systems with 40 amp output and four yellow wire stator configuration

• Mariner 135HP / 150HP / 175HP / 200HP V6 two-stroke applications using the same 18736A21 dual-regulator charging-system family

• HP Range: 135HP - 200HP

• Engine Type: Mercury / Mariner V6 two-stroke outboard

• Year Range: 1989 - 1991 for core 40 amp V6 charging-system applications

• Charging System: 40 amp, six-cylinder, four yellow wire stator configuration

🔌 Function

The voltage regulator / rectifier converts AC stator output to DC charging voltage and regulates that output to protect the battery, ignition electronics and vessel electrical system.

Common signs of failure:

• Battery not charging while engine is running

• Charging voltage too high or unstable

• Tachometer drop-out caused by charging circuit faults

• Regulator overheating or melted wiring

• Blown charging-system fuse or repeated battery issues

• Burnt yellow stator wires or damaged regulator connectors

• Electrical accessories cutting out due to voltage fluctuation

📦 Condition

• Genuine used part

• Removed from running engine where applicable

• In good working condition unless otherwise stated