Metra Car Audio & Video - Recent Questions, Troubleshooting & Support

The issue you're describing with your Nakamichi NA6605 head unit muting itself after installing new Infinity speakers could be caused by a few different factors. Let's go through some troubleshooting steps to help pinpoint the problem: 1. **Impedance Mismatch:** You mentioned that you replaced the factory speakers with Infinity 6x8 REF-8632cfx speakers. These Infinity speakers have an impedance of 3 ohms, while the original speakers were likely 4 ohms. This difference in impedance could potentially cause issues with the head unit's output stage. Some head units are designed to handle a specific range of speaker impedances. Make sure the Nakamichi unit is compatible with 3-ohm speakers. If it's not, this impedance mismatch could indeed lead to the behavior you're experiencing. 2. **Wiring and Connections:** Double-check all your wiring connections. Make sure that the speaker wires are properly connected and that there are no loose or exposed wires that could be causing a short circuit. Incorrect wiring can cause the head unit to detect a fault and enter mute mode. 3. **Power Supply and Ground:** Ensure that the head unit is receiving a stable power supply and that the ground connection is solid. Voltage drops or poor grounding can lead to unstable operation. 4. **Short Circuit Protection:** Many modern head units have built-in protection mechanisms that detect short circuits or incorrect impedances. If the head unit detects a problem, it might enter mute mode to prevent damage. Check the head unit's user manual to see if it has any relevant protection features. 5. **Head Unit Settings:** Check the Nakamichi unit's settings, especially those related to speaker impedance or output settings. Some head units allow you to adjust output settings based on the connected speakers. 6. **Firmware Update:** If there's a firmware update available for your Nakamichi head unit, consider updating it. Firmware updates can sometimes resolve compatibility issues. 7. **Test the Speakers:** To rule out the possibility of a faulty speaker causing the issue, you can temporarily disconnect the Infinity speakers and see if the head unit behaves differently. 8. **Professional Inspection:** If none of the above steps resolve the issue, it might be best to seek the assistance of a professional car audio installer or technician. They have the expertise and tools to diagnose and address complex issues with car audio systems. Remember, electrical issues in car audio systems can be complex and require a methodical approach to troubleshooting. If you're not comfortable diagnosing the issue yourself, it's best to seek professional assistance to ensure a safe and accurate resolution.

is radio comparable with the vehicle and or has it been hooked up correctly

Check for a sticker inside the glove box.
If the radio is stock and never been replace for day one then the code will match.
I included a sample picture of the stick below. This picture is just a sample. *****DO NOT USE the code on the picture.*****

Please look for the stick inside the glove or the radio mounting frame (you will need to pull the factory radio out ///not on the radio)



Please email if you need information on how to enter the security code.

It’s a ground, if your amp still won’t turn on after u finished installing Then use brown one as a ground and ground it to the same one as your amplifier.

You can buy an aftermarket radio harness adapter for your Navigator from ebay quite cheaply. I would not recommend butchering the factory wiring to install a replacement head unit. I found this one (will work as long as your Lincoln wasn't fitted with SATNAV) - Lincoln Radio WIRE HARNESS INSTALL STEREO PLUG 2003 09 eBay

Maybe burnt out bulbs,,, ck here for replacement.... https://www.youtube.com/watch?v=ChM3Oz-naDY

You need to make sure the amp turn on lead is connected... its blue with a white stripe

DISCONNECT BATTERY AND RE CONNECT

The blue lead does not go to negative. It needs to go to the power antenna wire from your radio. If you have an aftermarket radio, then this would be a solid blue wire from the aftermarket radio harness, that should be connected to the matching blue wire in your other store bought Toyota harness that it mates to. Then this plugs into the OEM harness that is part of your truck wiring. You can confirm that the blue wire at your power antenna is the one that triggers the motor by briefly touching it to the power wire (red) and watching your antenna begin to rise up. Remove the blue wire from power, and it should descend. If you need further help, I’m available over the phone at https://www.6ya.com/expert/reginald_bec291de192ca44f