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Metra 70-1857 Bypass Harness

Allows you to connect a new car stereo in select Bose®-equipped 1990-96 GM vehicles

Item # 120701857

Metra's 70-1857 bypass harness lets you replace the factory radio in select Bose®-equipped 1990-96 GM...

Read more from Crutchfield writer, Zak B.

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In Stock
$34.99

About the Metra 70-1857 Bypass Harness

Metra's 70-1857 bypass harness lets you replace the factory radio in select Bose®-equipped 1990-96 GM vehicles using the existing wiring and connectors. This harness bypasses the remote tuner in certain vehicles, while retaining use of the Bose® audio system. Warranty: 1 year.

Metra's 70-1857 bypass harness lets you replace the factory radio in select Bose®-equipped 1990-96 GM vehicles using the existing wiring and connectors. This harness bypasses the remote tuner in certain vehicles, while retaining use of the Bose® audio system. Warranty: 1 year.

Please enter your vehicle information or call an Advisor at 1-888-955-6000 to find out if this model is compatible with your vehicle.

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What's in the box:

  • Receiver wiring harness (includes antenna cable)

Customer reviews

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Metra 70-1857 Bypass Harness Reviews

Average Customer Review(s):

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Crutchfield response

More details on the Metra 70-1857 Bypass Harness

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Features

Crutchfield Wiring Harness: Crutchfield wiring harnesses prevent you from having to cut your vehicle's factory radio plug when replacing your factory radio with an aftermarket head unit. Simply solder or crimp the Crutchfield wiring harness to your aftermarket head unit's harness (solder & crimps not included), plug the aftermarket head unit's plug into the rear chassis of the aftermarket head unit, and plug the Crutchfield wiring harness into your vehicle's factory radio plug.

Note: Installation tools, hardware, & accessories are not included & sold separately. Please see the Accessories tab for recommendations & availability.

Wiring Notes: If the Crutchfield wiring harness is not equipped with a ground wire, you will need to ground the aftermarket head unit's ground wire to the metal chassis of your vehicle. Some vehicle's may require you to bypass the vehicle's factory amplifier (in another location from factory radio) or hardwire certain connections. If your vehicle is equipped with factory steering wheel controls, an additional adapter is required & sold separately.

Wire Code Chart:

Wire Color Function
Black (thick cable) Antenna Cable
Red +12 Volt Accessory
Yellow +12 Volt Constant
Black (3) Ground
Blue Power Antenna
White RCA Left Front Channel
Gray RCA Right Front Channel
Green RCA Left Rear Channel
Violet RCA Right Rear Channel

Notes:

  • There are three ground wires in the harness; all three should be connected to the new receiver's ground lead.
  • The male RCA plugs on the harness are plugged into the front and rear line-level outputs on the new receiver.

The Crutchfield Car Selector: Please visit the Crutchfield Car Selector for your specific vehicle.

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Customer Q&A

Q
Crutchfield asked: Why did you buy this?
A
Recommended by Crutchfield; and I would to preserve my factory connectors where possible. [ Greg  Sep 20, 2018 ]
A
Need it to wire up to amp, no alternative. [ Scott  Jul 03, 2018 ]
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suggested [ jeffrey  Jul 03, 2018 ]
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Included free and recommended by Crutchfield [ Chris  May 06, 2018 ]
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Recommended by Crutchfield and "FREE" [ Craig  Mar 29, 2018 ]
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Just to make sure I got it all before installation. [ Gerald  Mar 22, 2018 ]
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They are a perfect fit for my Cadillac, from antenna wire down to rca's. "IT'S A SNAP AND A TWIST". [ Ryan  Nov 28, 2017 ]
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Was recommended by Chad for my installation at no charge. [ B  Oct 04, 2017 ]
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Recommended by advisor [ Richard  May 01, 2017 ]
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Site recommendations [ Stanley  Apr 28, 2017 ]
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needed to easily interface after market reciever into specific vehicle and retain as is vehicle wiring harness [ William  Feb 20, 2017 ]
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this eliminates problems with old Bose system [ christopher  Dec 13, 2016 ]
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adapter cable for stereo, needed and good price [ Kim  Jun 28, 2016 ]
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came with kit [ DENNIS  May 15, 2016 ]
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New head unit for 1991 Corvette ZR-1 [ Peter  Jan 26, 2016 ]
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2 questions already asked

Q
Installed an aftermarket amp, and speakers, but my headunit will not turn on when I start the car, will this solve the problem of my headunit not working? And will I still be able to hook up my aftermarket parts to the headunit?
[ kenzi  Jul 31, 2016 ]
1 answer
A
If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer. You can also post your question in our forums: http://community.crutchfield.com. Or try our online support center: http://crutchfield.custhelp.com/app/answers/list/kw/.
[ Krissy  Aug 01, 2016 ]  Staff
Q
Does the 70-1857 connect the head unit? For 1994 cadilac Deville Concours
[ John  Mar 21, 2016 ]
1 answer
A
You can check to see if this will fit your vehicle by using our Outfit My Car tool: http://www.crutchfield.com/car/carselector.aspx For additional details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle.
[ Krissy  Mar 21, 2016 ]  Staff

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