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Metra 70-1677-1

Wiring Harness for Select 1978-1993 GM/Chevrolet Vehicles

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List price $19.99

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Arrives by Friday, Oct. 28 to zip 20147

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Metra Audio Store

Product Features:

  • Car Harness for select 1973-1993 GM/Chevrolet Vehicles
  • Plugs into car harness
  • One 12-pin plug and one 2-pin plug
  • Original high quality factory plug
  • High impact ABS OEM plastic molded connectors provide a perfect fit
  • OEM Quality terminals
  • Allows for the installation of an aftermarket radio using the existing factory wiring and connectors
  • 1-year Manufacturers warranty


  • Yellow – 12V Constant
  • Red – 12V Accessory
  • Black - Ground
  • Orange – Dash Light Dimmer/Illumination
  • Green – Left Rear Speaker (+)
  • Green with Black Stripe Left Rear Speaker (-)
  • White – Left Front Speaker (+)
  • White with Black Stripe – Left Front Speaker (-)
  • Purple – Right Rear Speaker (+)
  • Purple with Black Stripe – Right Rear Speaker (-)
  • Gray – Right Front Speaker (+)
  • Gray with Black Stripe – Right Front Speaker (-)

Compatibility List:

  • Buick:
    • 1982 - 1987 Century
    • 1984 - 1987 Electra
    • 1984 - 1987 Le Sabre
    • 1984 - 1987 Regal
    • 1983 - 1987 Regal T-Type
    • 1984 - 1985 Riviera
    • 1982 - 1987 Skyhawk
    • 1983 - 1986 Skylark
  • Cadillac:
    • 1982 - 1988 Cimarron
    • 1985 - 1987 Coupe De Ville
    • 1983 - 1987 El Dorado
    • 1985 - 1987 Fleetwood
    • 1984 - 1987 Sedan Deville
    • 1984 - 1987 Seville
  • Chevrolet:
    • 1985 - 1990 Astro
    • 1978 - 1991 Blazer
    • 1982 - 1989 Camaro
    • 1985 - 1990 Caprice
    • 1982 - 1990 Cavalier
    • 1979 - 1989 Corvette
    • 1982 - 1987 El Camino
    • 1985 - 1989 Impala
    • 1981 - 1988 Monte Carlo
    • 1983 - 1989 S-10 Blazer
    • 1982 - 1988 S-10 Pickup
  • Oldsmobile:
    • 1985 - 1993 98
    • 1985 - 1989 Cutlass Calais
    • 1987 - 1987 Cutlass Ciera
    • 1984 - 1989 Cutlass Supreme
    • 1988 - 1989 Touring Sedan
  • Pontiac:
    • 1982 - 1989 6000
    • 1985 - 1991 Bonneville
    • 1982 - 1989 Firebird
    • 1985 - 1989 Grand AM
    • 1985 - 1987 Grand Prix
    • 1982 - 1988 Sunfire

Harness Features

Vehicle Sound System
This refers to what kind of sound system the vehicle has. Premium audio systems are generally name brand systems (such as JBL, Bose, Rockford Fosgate, etc) that have been installed inside a vehicle when it leaves the factory. Often they more advanced systems, complex wiring, factory amplifiers, and other features that can make installing aftermarket component difficult.
Standard Sound
Main Harness Function
Different installations on different vehicles require different harnesses. This type is what the harness is considered. Each wiring harness we sell serves a purpose such as installing an aftermarket car stereo, integrating an aftermarket amplifier with your factory car stereo, connecting Bluetooth to your factory car stereo, and more.
Connect/Install an Aftermarket Car Stereo
Compatible Vehicle Make
Allows you to view only items that are compatible with your vehicle's make. Does not guarantee that it will work with your vehicle year or model.
Compatible Vehicle Make and Model
The model of vehicle that this vehicle specific product is designed for. Please keep in mind that engine variations can affect the compatibility of the products.
Buick Century
Buick Lesabre
Buick Regal
Buick Riviera
Cadillac Deville
Cadillac El Dorado
Cadillac Fleetwood
Cadillac Seville
Chevy Astro
Chevy Blazer
Chevy Camaro
Chevy Caprice
Chevy Cavalier
Chevy Corvette
Chevy Impala
Chevy Monte Carlo
Chevy S-10
Oldsmobile Cutlass
Pontiac Bonneville
Pontiac Firebird
Pontiac Grand Am
Pontiac Grand Prix
Pontiac Sunfire

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating


Tonganoxie Kansas

Factory OEM Harness Found!

April 3, 2014

This was a unique factory stereo harness that had me going CRAZY trying to locate the correct harness. I have been in Automotive management for 23 years and have watched electronic technology worm its way into everything related to the Automotive Industry. The days of "poking and proding" wires to find current have been long gone because this ancient practice invites corrosion and resistance a place to begin life. Metra's wonderful product allowed me to make a quick and simple connection and finish this job without disrupting my factory connectors. "Plug n Play." I will never look at anything but Metra's product line again! Thank You!

26 of 30 found this helpful

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UncleTony 1959

Phenix City, Alabama

Great Service very quick shipping

March 30, 2014

This made installation of my Eonon M1U easy as pie to install,didn't have to worry about getting wires mixed up. Not many companies have parts for my 1984 Buick Lesabre SONIC came thru for me would recommend them to all my friends. Stop searching the web for your electronic parts if SONIC doesn't have it you probably don't want it anyway!

24 of 28 found this helpful

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Walkersville, Md


May 26, 2016

This wiring harness is perfect fit. Installation time only took a small bit. For my application, this wiring harness is a hit!

Ordering from Sonic is a breeze. These people are not sleaze. Sonic knows their stuff! They are not gruff.

If you want your car stereo to be a perfect fit, order from Sonic. Then your car stereo will be symphonic. Because if it does not fit, you must acquit

Sonic is the best, the hell with the rest!!

0 of 0 found this helpful

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Richmond, KY

Great product

January 12, 2016

This product was a perfect fit for my Chevy.
The installation was relatively easy with a nice tight fit for the single din pioneer HU. Thanks Sonic Electronix's customer service.

0 of 0 found this helpful

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South Alabama

Verified Purchase
Perfect fit

November 30, 2015

I installed this on my new receiver and it was a perfect fit to my OEM C10/R10 truck. Must have when installing, makes it clean and less wiring issues...!

1 of 2 found this helpful

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Ashland, OH

great product

November 24, 2015

Absolute necessity for my installation, much more technical without it.

0 of 0 found this helpful

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Browse 2 questions and 5 answers
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Why did you choose this?
Sonic Electronix Store
has orange dimmer wire while scosche does not
Mark W on Sep 28, 2015
This is the cheapest radio harness I can get and its GM and guaranteed to fit my 1984 s-10 pickup.
Justin C on Aug 29, 2014
To interface with my Firebird
Bruce S on Sep 25, 2015
1984 has factory bose system.can I use this plug to put in aftermarket radio and still use the bose speakers?
Chris S on Aug 9, 2015
Best Answer: Chris, for a brief period, I used an after market head unit to drive all four Bose speakers in my 85 Corvette.

IN ADDITION to the Metra plug, you will ALSO need the Scosche OEA4 factory amp interface/adapter. It's a non-powered/passive adapter that will allow you to make use of the Bose speakers in conjunction with a higher powered after market head unit. It allows for proper gain adjustment so you don't overload the new head unit's amplifier circuitry. The Bose speakers in our Corvettes are rated at about 2 OHMS, while most after market speakers are rated at 4 OHMS, hence the creation of the adapter. I found it to be effective, simple, and a worthy solution if you don't have time to dig in to the vehicle's interior and swap the Bose speakers for after market speakers. (If you do so in the future, the Bose speaker pods will indeed accept after market speakers with slight modification)

Cheers, John
Scosche OEA4
Scosche OEA4
Reply · Report · John S on Aug 9, 2015
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Product Summary


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Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: Metra 70-1677-1