70-5521 - Kit auto Metra - Free user manual and instructions

Product Type	Receiver Wiring Adapter for Aftermarket Car Stereos
Brand	Metra
Model	70-5521
Compatible Vehicles	Select vehicles with factory radio harness (consult Metra or vehicle-specific guide)
Wire Connection Method	Crimp connections using supplied crimp caps or electrical tape
Power Input	12V DC (vehicle electrical system)
Wire Length	Approximately 6 inches (typical)
Number of Wires	Standard 12-pin configuration (wire functions: power, ground, speakers, illumination, etc.)
Wire Functions Included	Constant 12V, Switched 12V, Ground, Left Front (+/-), Right Front (+/-), Left Rear (+/-), Right Rear (+/-), Illumination (Orange)
Illumination Wire Handling	Tape off if new receiver does not have illumination wire
Ground Wire	Black wire – connect to receiver ground
Installation Tools Required	Wire stripper/crimp tool, crimp caps, electrical tape
Installation Steps	1. Match wires by function (ignore color). 2. Strip, twist, and crimp. 3. Tape unused wires. 4. Plug into factory harness.
Safety Precautions	Disconnect vehicle battery negative terminal before installation to prevent short circuit
Dimensions (Approx.)	4 x 2 x 0.5 inches (adapter body)
Weight (Approx.)	0.1 lb
Material	Plastic housing with color-coded copper wires
Maintenance	None required; keep connections secure and dry
Spare Parts Availability	Not applicable; adapter is single-use wiring harness
Repair	If damaged, replace entire adapter; no user-serviceable parts
Country of Origin	Not specified; likely China (typical for Metra accessories)
Certifications	Meets automotive industry standards for 12V systems
Warranty	Limited lifetime warranty (verify with retailer or Metra)
Manual Included	Yes, 2-page PDF with step-by-step instructions

Frequently Asked Questions - 70-5521 Metra

What is the Metra 70-5521 used for?

It is a wiring adapter that allows you to connect an aftermarket car stereo to the factory radio harness in compatible vehicles, simplifying installation without cutting or splicing wires.

How do I match the wires on the adapter to my new receiver?

Match wires by function, not by color. Refer to the receiver's manual for wire functions (e.g., constant 12V, ground, speaker outputs) and connect corresponding wires from the adapter.

What should I do if my receiver doesn't have an illumination wire?

If your receiver lacks an illumination wire, tape off the orange wire on the adapter with electrical tape and do not connect it.

Why is it important to disconnect the car battery before installation?

Disconnecting the negative battery terminal prevents short circuits, protects the stereo from electrical damage, and ensures safety during wiring.

Can I use the adapter without crimp caps?

Yes, you can solder and insulate with electrical tape, but crimp caps are recommended for a reliable connection and are included in most kits.

What do the different wire colors on the 70-5521 mean?

Typical wire colors: Yellow (constant 12V), Red (switched 12V), Black (ground), Gray/White (front right), Green/Purple (rear left/right), and Orange (illumination). Always verify with your vehicle.

Is this adapter compatible with all vehicles?

No, the 70-5521 is designed for specific vehicle makes and models. Check Metra's vehicle fitment guide or consult the product listing to confirm compatibility.

How do I tape off unused wires?

Wrap electrical tape around the stripped end of each unused wire to prevent short circuits. Ensure the tape covers the bare copper completely.

Can I reuse the adapter if I change my stereo?

Yes, you can reuse the adapter as long as the wire connections are intact. Simply remove the tape or crimps and reconnect to the new stereo following the same procedure.

What tools do I need for installation?

You need a wire stripper/crimp tool, crimp caps (often included), and electrical tape for insulating unused wires.

USER MANUAL 70-5521 Metra

Receiver Wiring Adaptor

IMPORTANT

120 70-5521

Before starting, compare items on your invoice with items received. Thoroughly check packing materials. If an item is missing, please call Crutchfield at 1-888-955-6000.

Revision 09/29/15

STEP 1 -- MATCH & CONNECT WIRES

A. Match wires below to the matching function of each wire on your receiver (refer to instructions supplied with receiver). The wire colors of your new receiver may, or may not, match the wire colors of the adaptor. Match adaptor and receiver wires by function, disregarding color.
B. If your receiver does not have an Illumination wire, tape off the Orange wire.
C. Connect Black wire to Ground wire of new receiver.
D. Individually tape off any unused wires.
E. Make final wiring connections following instructions on the next page.

Receiver Wiring Adaptor Connections

120 70-5521

STEP 2 -- CRIMP CONNECTIONS

Tools & Parts Required ▶

Wire Stripper/Crimp Tool Crimp Caps

A. Strip wires back 1/2".

Line drawing of a mechanical component with internal gears and a handle (no text or symbols)

B. Twist wires together and insert in crimp cap.

Diagram showing a cable being inserted into a plug, with an arrow indicating the insertion direction (no text or symbols present)

C. Squeeze middle of cap for tight connection.

STEP 2 -- CONTINUED

D. Complete crimp connections for all necessary wires.
E. Be sure to wrap any wires from the Wiring Adaptor that are not necessary (wires with no match from the new receiver) with electrical tape.

Receiver Wiring Adaptor

Generic Illustration

STEP 3 -- APPLICATION

When ready to install the receiver, plug the Wiring Adaptor from the new receiver or receiver assembly into the factory radio harness(es) in the vehicle dash.

Generic Illustration

CRUTCHFIELD®

Copyright 2013 Crutchfield Corporation