Metra 70-1857 Bypass Harness
Allows you to connect a new car stereo in select Bose®-equipped 1990-96 GM vehicles
Item #: 120701857
Your price: $34.99 Earn up to 35 Rewards points
Our experts help you pick the ideal gear for your needs.Meet our advisors
Free tech support for the life of your gear.Read about our one-on-one expert help
You may return items that are complete and like new for any reason within 60 days.See the details of our return policy
Earn one point for every dollar you spend and use those points to save on future purchases.Get full details on Crutchfield Rewards
We offer vehicle-specific installation instructions, dash kits, wiring harnesses, and speaker accessories at deeply discounted prices with car stereo and speaker purchases. Available for most vehicles.Learn more
Our customers have trusted us with their business, and they’ve helped us win awards for our service.Check out our most recent awards
The manufacturer’s warranty always applies.See more details
Item #: 120701857
Your price: $34.99 Earn up to 35 Rewards points
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.
Note: Most vehicles will require additional installation parts please identify your vehicle if you haven’t done so. You can also call an Advisor for more information.
Was very easy to install and had plenty of length to reach where I needed it to.
Pros: Long wires Well labeled Easy to install
Great interface, but 6' of extra cable
Pros: Works perfectly
Cons: I had about 6' of extra cable when finished. A cable designed for specific autos would be great.
This was a huge help with replacing the Factory Bose unit in my 94 corvette. It has all of the connections you need. There are no instructions but basically you need to check out the instructions at ZIP corvette. You will need to run the wires along the passenger side of the car. (Zip recommends removing the seat but I didn't need to do that. It's a big job but well worth it.
Pros: Good cost. Everything you need for the job
Cons: None - This is a weekend project but that has nothing to do with this harness.
Awesome, works as described! fast shipping!
Pros: Perfect fitment!
THE HARNESS WAS VERY HELPFUL
Pros: DIDN'T HAVE TO CUT WIRES
Ordered the wrong wiring harness even after talking to a consultant that advised me of a possible error I had made but I didn't listen to him. Great products/Great people/Great Company!! Have the right part now after swapping out. I have dealt with Crutchfield before on other products & vehicles and cannot put into words how impressed I am with all aspects of this Company. You will always have my business and I am recommending your Company to all my friends and family . Your Professionalism, Product support, Outstanding Staff are what is all about. Wish the rest of America would figure that out! Great job!!
Pros: Professional, Knowledgeable Product & Customer Support Outstanding ,
A well made harness but it was only a little helpful and I only used some of it . I believe this was because of my vehicle type which is a 1992 corvette with a Bose system but on another Chevrolet product I think it would be fine
Pros: It had some parts necessary to connect to existing connectors
Cons: I still had to buy wire and wire up all the speakers
Pros: All wires were correct. Nice to be able to plug into the harness without running all new wires and I was able to use the original BOSE Amps and speakers.
Cons: The wiring only needed to be about 5 to 6 feet long and was probably 20 feet long. The RCA and Antenna wires are already finished with plugs on both ends so I didnt' want to cut those. Just wound them up, zip tied them and put them under the dash.
While supposedly this was meant for my '95 corvette, and the instructions were fine, it somehow didn't quite fit the way I envisioned it. The product itself was great, and very long which turned out to be useful.
Pros: good product, worth the money
Cons: didn't fit the way I thought it would
I just want to say thank you so much to the crutchfield team of techs that helped me install my stereo I had to call a couple of times for help . My stereo sounds excellent once again thank you . I have since recommend crutchfield to my friends .
Pros: Great selection of product at a great price .
Cons: Can't say anything bad .
This adapter is the perfect answer to the problem of connecting to a bose amplified speaker system. It would be a bargain at twice the price.
Pros: There really is no better way to connect an aftermarket head unit to a factory bose system. super easy plug and play install.
Cons: The cables can be much to long for some applications and become difficult to package.
The cable itself was awesome. The directions only included a wiring diagram; no instructions. In the case of a Corvette Bose system, this cable is intended to connect to the hidden pre-amp behind the seat. In my case I believed it connected into the wire harness behind the head unit, but the connectors would not match up. Nothing in the included paperwork indicated this. I will say, though that one call to the Crutchfield Help desk solved the issue in under 2 min. The tech knew immediately the specifics of the '96 Corvette and pointed out where the cable connected. It was very refreshing to have someone pick up the phone immediately and speak clearly, in proper English as well! High five to Crutchfiled!
Pros: This cable mates to the stock Bose system with perfection. I would have given 5 stars for better instructions
Cons: The instructions tell you little and are simply a wiring diagram.
Harness is 17 feet long which may be required for some applications. 6 feet length would have worked for my application. The power leads can be cut down but the amplifier leads would be more difficult and you would require a shorter antenna lead.
Ordered this for my HD pioneer, for my 91 Corvette base model with Bose system. This is allowing the faders to work. It simplified everything!!! Not confusing at all either. Troy was very helpful in finding what i needed. Thanks!!!!
Pros: Simple, organized, color-coded, problem solving
Perfect adapter and quality connections. Be prepared to have a lot of wire. It weighs a few pounds, and is enough wire to span the length of a SUV!
Pros: Perfect fit
Cons: A lot of wire that you'll have to hide as there is no cutting the RCA cables. I estimate 10' of wire.
Without this, the installation would have been a nightmare
Pros: Easy install. Great instructions and phone support
Very good Quilty wires and plug.........
Pros: Lots of wire!!!
Cons: Way to long of an antena wire does not need to be 10 foot long maybe 6 foot at the most!!! the problem is you have to make the dash fit together but it did you have to just have to think outside the box and you'll find a spot to hide the wires........
didnt come with line filters
Pros: long wires
Cons: no line filters
After a couple discussions with the tech at Crutchfield, the harness was pretty easy to figure out, worked great.
Pros: All conections to were well researched by Crutchfield.
Installed on 1992 corvette with Bose system worked excellent. Attached aftermarket head unit to bose speakers. Only down fall to much wire for my application should be more tailored to vehicle.
Pros: Worked as intended
Cons: To much wire for application
Had no instructions
Cons: Need info to hook upCrutchfield response on May 30, 2012 Thanks for your comment. This adapter works in many different vehicles, and we do offer complete instructions for most of them. If you need information that doesn't come with your product, our tech support specialists can provide it over the phone.
A helpful piece for and easier install. I used it in my 92 cadillac eldorado with bose!
Pros: Sounds and works well!
Cons: when turning the radio on makes a thump sound. but other than that pretty clear!
helpful easy to install but there is some unwanted noise the most difficult stereo ive done yet 1994 cadillac eldorado with bose stereo
Pros: stereo works now
Cons: lousy sound
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:
|Black (thick cable)||Antenna Cable|
|Red||+12 Volt Accessory|
|Yellow||+12 Volt Constant|
|White RCA||Left Front Channel|
|Gray RCA||Right Front Channel|
|Green RCA||Left Rear Channel|
|Violet RCA||Right Rear Channel|
The Crutchfield Car Selector: Please visit the Crutchfield Car Selector for your specific vehicle.
At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.
New head unit for 1991 Corvette ZR-1 [ PETER Jan 26, 2016 ]