Small Frame Alternator, 12 Volt, 78 Amp, 20053

Small Frame Alternator, 12 Volt, 78 Amp, 20053
SKU: 76873
Mfg# 20053
UNIT: Each
Description: Small Frame AlternatorVoltage: 12Rated Output: 78
Typically Ships Out in 2 Business Days
Small Frame Alternator, 12 volt, 78 amp, 20053.

  • 20053 (New 12 volt, 78 amp)
  • Fits Mercury, OMC, Volvo & others
  • Can replace Mando & Motorola
  • Replaces Merc #'s 78477, 78403A 2
  • Delco Style, 10SI, Ignition Protected
  • 3-Wire Hook-Up w/ Neg. Ground

  • Red Wire is for Sensor
  • Black Wire is for Excitation

  • 20053 can be interchanged with 20054

API 1-wire alternators may need additional engine rpm over idle speed to activate internal voltage regulators. Simply rev the engine and alternator will excite and charge properly. This situation is due to high output performance of API Marine alternators of 78-94 amps. A 3-wire version of any of the 1-wire alternators may be substituted and the alternator will be activated by the key switch. API #s 20030. 20037. 20044. 20051. 20075. 20091 & 20092.

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All products sold by API Marine are warranted for a period of one (1) year from the date of actual purchase. Warranty against defects in material and workmanship are the sole and exclusive warranty provided by API.


  • Restocking charge will apply at a minimum of 10% for all product returned.
  • All Returns must be returned within 30 days of receipt of the items.
  • Some products are non-returnable, please contact us for further details.
  • Manufacturer defects reported within 30 days of receipt will be supplied a pre-paid label for return shipping upon approval.
  • Please contact Go2marine LFS Marine and Outdoor for Manufacture Defects, Returns and help with Warranties.