FAQ
TL;DR: For Opel Corsa D/Quadlock-to-ISO installs, 1 blue antenna-control wire powers only when the radio is on — “Blue cable gives power to the antenna after switching on the radio.” Map yellow=BAT+, red=ACC, and correct any mispinned adapters. [Elektroda, Pedros050, post #17007770]
Why it matters: This avoids no-sound, memory-loss, or antenna issues when fitting aftermarket 1DIN radios in Opel vehicles.
Quick Facts
- Yellow wire feeds constant +12 V (battery) for radio memory/presets. [Elektroda, k52, post #17007452]
- Red wire is ignition-switched +12 V; you can tie the blue remote to it if needed. [Elektroda, Pedros050, post #17007521]
- Blue wire is the antenna/amp remote; it energizes only with the radio on. [Elektroda, Pedros050, post #17007770]
- Opel Corsa D uses a Quadlock; use an ISO–Quadlock adapter for Sony/JVC 1DIN units. [Elektroda, Pedros050, post #17007296]
- Final outcome: after repinning the adapter, the system played correctly in the Corsa D. [Elektroda, k52, post #17017153]
Which wire on the ISO harness is constant 12 V in an Opel Corsa D?
Use the yellow lead for constant battery power. It maintains presets and clock memory. This thread confirms yellow goes to the battery feed in the Opel-to-ISO setup. Ensure the adapter’s yellow is on the Quadlock’s permanent +12 V pin before final assembly. [Elektroda, k52, post #17007452]
Which wire is the ignition-switched (ACC) feed?
The red lead is the ACC feed. It powers the radio only when the key is on. You can also piggyback the antenna/amp remote (blue) to the red ACC if your antenna amplifier expects switched power from the ignition. “Then the amplifier will work.” [Elektroda, Pedros050, post #17007521]
What does the blue wire do on Opel/ISO radio looms?
Blue is the antenna/remote amplifier control. The head unit outputs +12 V on this wire only when the radio is turned on. This triggers an amplified roof antenna or a powered mast. Quote: “Blue cable gives power to the antenna after switching on the radio.” [Elektroda, Pedros050, post #17007770]
Do I need the blue wire if my roof antenna isn’t amplified?
No. If your antenna has no built‑in amplifier or electric mast, you don’t need to connect the blue lead. The radio will still receive through a passive antenna path. If reception is weak, verify whether your model actually includes an amplifier before adding the blue feed. [Elektroda, Pedros050, post #17008097]
Where should the loose red wire from my ISO harness connect on the Opel Quadlock?
Connect the red ISO wire to the Quadlock’s ignition-switched +12 V position. This ensures the radio turns off with the key and prevents battery drain. If your antenna amp needs switched power, you may tie the blue remote to this red ACC feed. [Elektroda, Pedros050, post #17007521]
How many power-related pins should I expect on the Opel Quadlock?
Expect two power pins: one permanent +12 V and one ignition-switched +12 V. This matches the discussion where the layout shows two distinct power positions in the Opel cube before repinning the adapter. Verify these before powering your new head unit. [Elektroda, k52, post #17007452]
How do I adapt an Opel Quadlock to an aftermarket ISO radio?
Use a Quadlock-to-ISO adapter harness and follow the provided pin diagram. Plug Quadlock into the car, ISO ends into the new radio harness, then secure the cage and trim. This is the recommended path for Sony/JVC 1DIN units. [Elektroda, Pedros050, post #17007296]
Quick 3-step: How to wire an aftermarket radio in a Corsa D?
- Fit a Quadlock→ISO adapter and confirm pin mapping against the diagram.
- Connect yellow=BATT+, red=ACC, blue=ANT/REMOTE, black=GND on the ISO side.
- Test power and FM reception before final mounting.
[Elektroda, Pedros050, post #17007296]
My adapter seems mispinned. What’s the fix?
Repin the adapter so yellow goes to permanent +12 V and red to ACC in the Opel Quadlock. After correcting the pins, the poster reported a clean install and proper operation. Symptom resolution included stable power and good audio. [Elektroda, k52, post #17017153]
Will a 1DIN Sony or JVC fit and work with this approach?
Yes. The thread’s Corsa D used a fascia kit plus Quadlock→ISO, then an ISO→radio lead to a 1DIN Sony/JVC. After mapping the power and remote leads correctly, the setup worked as expected. Ensure the frame and pocket are secured before driving. [Elektroda, k52, post #17007588]
Does the radio supply power for the roof antenna amplifier?
Yes. When you select the tuner, the head unit’s blue wire outputs +12 V for an amplified roof antenna. This is how many aftermarket units control antenna amplifiers and powered masts. “The player sends the voltage on the blue cable to this antenna amplifier.” [Elektroda, k52, post #17008087]
I see different Opel pinouts online—could my diagram be for another radio?
Yes. Some diagrams reference the Opel CD30/MP3 (Blaupunkt) pinout, which may differ from your unit or adapter. Always match your vehicle’s harness to the adapter scheme before powering up. Misalignment here is a common cause of no‑power issues. [Elektroda, Pedros050, post #17007554]
Can I link the blue remote to red ACC to wake an antenna amplifier?
Yes. If your antenna amp needs switched power with ignition, connect blue to red ACC. This gives the amplifier power when the key is on and the radio requests it. It’s a practical workaround when the car loom doesn’t feed the amp separately. [Elektroda, Pedros050, post #17007521]
How do I know the final wiring works before full install?
Bench‑test in the dash opening: power on, verify presets save (yellow), confirm key‑off behavior (red), and check FM strength with blue connected. The poster did a short test fit first, then finalized the mount after confirming success. [Elektroda, k52, post #17007705]