1. Utangulizi
This manual provides instructions for the Metra 70-9003 Radio Wiring Harness. This harness is designed to simplify the installation of an aftermarket radio into select Audi, BMW, and VW vehicles manufactured from 2002 onwards. It eliminates the need for cutting factory wiring, ensuring a clean and straightforward connection.
2. Yaliyomo kwenye Kifurushi
- Metra 70-9003 Wire Harness
- Mwongozo wa Maagizo

Image: The Metra 70-9003 Radio Wiring Harness as it appears in its retail packaging, showing the product label and part number.
3. Vipimo
| Chapa | Metra |
| Nambari ya Mfano | 70-9003 |
| Nyenzo | Kloridi ya Polyvinyl (PVC), Polyethilini (PE) |
| Vipimo vya Kipengee (L x W x H) | Inchi 7.75 x 4.5 x 2 |
| Uzito wa Kipengee | Wakia 0.8 (g 22.68) |
| Aina ya kiunganishi | Programu-jalizi |
| Matumizi Yanayopendekezwa | Ubadilishaji wa Redio |
| Kipenyo cha Waya | Mil 18 |
| Utangamano | Audi/BMW/VW 2002-Up (Confirm with Metra Vehicle Fit Guide) |
4. Maagizo ya Ufungaji
4.1 Jumla Zaidiview
The Metra 70-9003 harness is designed for direct plug-and-play integration with your vehicle's factory radio connectors. The color-coded wires on the aftermarket radio side simplify connections, eliminating the need for cutting the vehicle's original wiring.
4.2 Kabla ya Kuanza
- Ensure your vehicle is compatible with the Metra 70-9003 harness. Refer to the Metra Electronics Vehicle Fit Guide or contact Metra tech support for confirmation.
- Tenganisha sehemu hasi ya betri ya gari ili kuzuia kaptula za umeme wakati wa usakinishaji.
- Gather necessary tools, which may include wire strippers, crimpers, electrical tape, and a multimeter.
4.3 Viunganisho vya Wiring
Match the color-coded wires of the Metra 70-9003 harness to the corresponding wires of your aftermarket radio's harness. Common wire functions are listed below:
- Za: 12V Constant Power
- Nyekundu: 12V Accessory Power (Switched)
- Nyeusi: Ardhi
- Bluu: Antenna ya Nguvu / AmpWasha Kijijini cha Lifa
- Chungwa: Mwangaza
- Waya za Spika: (Green, Purple, Gray, White - solid for positive, striped for negative)
Secure all connections using crimp connectors or solder, and insulate them with electrical tape or heat shrink tubing to prevent short circuits.

Image: The Metra 70-9003 Radio Wiring Harness, displaying its vehicle-specific connector and the color-coded wires for aftermarket radio integration.
4.4 Kuunganisha na Gari
Plug the vehicle-specific connector of the Metra 70-9003 harness into the factory radio harness located in your dashboard. Then, connect the aftermarket radio's harness (which is now wired to the Metra harness) to the new radio unit.
4.5 Testing and Reassembly
- Unganisha tena kituo cha betri hasi cha gari.
- Turn on the vehicle and test the aftermarket radio's functions, including power, audio output (all speakers), balance, fade, and illumination.
- If all functions operate correctly, carefully reassemble the dashboard components.
5. Maagizo ya Uendeshaji
The Metra 70-9003 is a passive wiring harness that facilitates the electrical connection of an aftermarket radio. Its operation is entirely dependent on the functionality of the connected aftermarket radio. Refer to your aftermarket radio's instruction manual for specific operating procedures and features.
6. Matengenezo
The Metra 70-9003 wiring harness requires no regular maintenance. To ensure continued performance, periodically check that all connections remain secure and are free from moisture, corrosion, or physical damage. Avoid pulling on the wires or connectors forcefully.
7. Utatuzi wa shida
7.1 No Power to Radio
- Check the vehicle's fuse box for blown fuses related to the radio or accessory power.
- Verify the 12V constant (Yellow) and 12V accessory (Red) wires are correctly connected and receiving power using a multimeter.
- Hakikisha betri ya gari imechajiwa kikamilifu na imeunganishwa ipasavyo.
7.2 Hakuna Sauti kutoka kwa Spika
- Confirm all speaker wires (Green, Purple, Gray, White - solid for positive, striped for negative) are correctly matched and connected to the aftermarket radio.
- Check the aftermarket radio's settings for proper balance and fade.
- Ikiwa ya nje amplifier is used, ensure the remote turn-on wire (Blue) is connected and the amplifier inapokea nguvu.
7.3 Radio Not Turning Off with Ignition
- Verify the 12V accessory (Red) wire is connected to a switched power source that turns off with the vehicle's ignition.
7.4 Masuala ya Jumla
- Double-check all wiring connections for looseness or incorrect pairing.
- Consult the aftermarket radio's manual for specific troubleshooting steps.
- For further assistance, contact Metra tech support.
8. Udhamini na Msaada
8.1 Taarifa ya Udhamini
The Metra 70-9003 Radio Wiring Harness comes with a 1-year limited warranty. Please retain your proof of purchase for all warranty claims.
8.2 Msaada wa Kiufundi
Metra provides technical support 7 days a week for installation assistance. For contact information, please refer to the product packaging or visit Metra's official webtovuti.