Mercury MerCruiser OEM Neutral Safety Switch - 8M0052939

Compatible Applications

Mercury 8M0052939 / 8M0207794 is used in a broad range of Mercury Marine shift systems. The supplied Mercury fitment includes outboard, Verado, Pro XS, racing, sterndrive, inboard and TowSports applications.

Because the same switch is used across several different engine and shift systems, always verify the model, serial number and OEM part number.

Mercury / Mariner 3.0L Outboards

Mercury DFI, Pro XS and Sport XS Applications

Mercury Racing and Special Performance Applications

Mercury V6 2.5L Applications

Mercury Verado Applications

Mercury 75-115 HP EFI Applications

MerCruiser Sterndrive Applications

Mercury Diesel / CMD Applications

OEM and Cross Reference Numbers

Pro Marine Replacement Available

Pro Marine Neutral Safety Switch - 52939P

Pro Marine also stocks an aftermarket replacement switch for the same compatible Mercury Marine applications.

Choose between the genuine Mercury OEM switch and the Pro Marine 52939P aftermarket replacement.

View Pro Marine 52939P Neutral Safety Switch

What This Part is Used For

The neutral safety / shift position switch provides the engine or control system with information about the position of the shift mechanism.

On applications where it serves as a neutral safety switch, it is part of the starting-safety circuit that helps prevent the engine from starting while the transmission or gearcase is in gear.

Mercury also uses this switch in several mechanical and Digital Throttle and Shift (DTS) systems, which is why the same OEM switch appears in outboard, sterndrive, inboard and diesel applications.

Common Symptoms of a Neutral Safety or Shift Switch Problem

• Engine will not crank even though the control is in neutral
• Intermittent no-crank condition
• Engine starts only when the control lever is moved slightly
• Incorrect or inconsistent shift-position indication
• DTS or shift-related fault after other causes have been eliminated
• Physical damage to the switch or actuator
• Corrosion or damage at the electrical connector

These symptoms can also be caused by wiring, linkage adjustment, control-box problems or other starting-system components. Diagnose the system before replacing the switch.

Installation and Replacement Tips

• Disconnect battery power before servicing the shift or starting circuit.
• Confirm the OEM switch number before removing the original part.
• Note the position and adjustment of the original switch.
• Inspect the electrical connector and wiring for corrosion or damage.
• Inspect mechanical shift linkage for wear or improper adjustment.
• Install and adjust the switch according to Mercury service procedures.
• Verify proper forward, neutral and reverse operation after installation.
• Where applicable, verify the engine starts only in neutral.
• On DTS applications, follow the appropriate Mercury diagnostic procedure.

Key Features and Benefits

• Genuine Mercury Marine OEM component
• Mercury item number 8M0052939
• Current Mercury replacement number 8M0207794
• Fits numerous Mercury and Mariner outboard applications
• Fits select Mercury Verado and Pro Verado models
• Fits select Mercury Pro XS, XS and racing outboards
• Fits select MerCruiser sterndrive applications
• Fits select MerCruiser inboard and TowSports applications
• Used in mechanical and DTS-related shift systems depending on application
• Replaces earlier Mercury 889514A01 and 814281A7 numbers
• Pro Marine aftermarket version also available

FAQ

Is 8M0052939 a genuine Mercury part?
Yes. This listing is for the genuine Mercury Marine OEM switch.

What replaced Mercury 8M0052939?
Mercury has superseded 8M0052939 to 8M0207794.

Will 8M0207794 replace 8M0052939?
Yes. 8M0207794 is the current Mercury functional replacement for 8M0052939.

Does this replace 889514A01?
Yes. 889514A01 is an earlier Mercury part number in the replacement family.

Does this replace 814281A7?
Yes. 814281A7 is also an earlier Mercury number in the replacement chain.

Does this switch fit Mercury Verado?
Yes. The supplied fitment includes many 135-350 HP Verado applications, including 4-cylinder, 6-cylinder and Pro Verado models. Verify the serial range above.

Does it fit Mercury Pro XS?
Yes. The supplied Mercury data includes multiple Pro XS applications, including 2.5L and 3.0L models.

Does 8M0052939 fit MerCruiser?
Yes. The supplied Mercury fitment includes multiple MerCruiser sterndrive, inboard and TowSports applications, including 496 MAG, 5.0L MPI, 350 MAG, 377 MAG, 8.2L and CMD / TDI diesel models.

Is this strictly a neutral safety switch?
It is commonly used as a neutral safety / shift position switch, but Mercury uses the same switch in several different mechanical and DTS shift assemblies depending on the application.

Can I determine fitment by horsepower alone?
No. This switch covers many different Mercury engine families. Verify the model, serial number and OEM part number before ordering.

Do you carry an aftermarket version?
Yes. Pro Marine also stocks the Pro Marine 52939P Neutral Safety Switch .

Searchable Part Numbers

8M0052939, 8M0207794, 87-8M0052939, 87-8M0207794, 889514A01, 814281A7, 879150T94

Searchable Terms

Mercury OEM neutral safety switch, Mercury neutral switch, Mercury shift switch, Mercury shift position switch, Mercury outboard neutral safety switch, Mercury Pro XS shift switch, Mercury Verado shift switch, Verado neutral safety switch, Mercury DTS shift switch, MerCruiser neutral safety switch, MerCruiser shift switch, MerCruiser DTS switch, 8M0052939 switch, 8M0207794 switch