How to Fix the Current Noise in Navigation System?
3 Answers
Generally, the reason is poor grounding of the navigation system, which introduces external interference into the circuit of the navigation system. You can purchase a rectifier and connect the navigation power supply to the rectifier for charging.
I've encountered many issues with navigation system current noise, mostly due to poor ground connection. You can first check if the yellow power cable behind the head unit is loose, especially whether the grounding wire has rusted. Remember to turn the car key to ACC position for testing - don't work on it with power on as you might accidentally touch metal. Last time when helping a friend fix this, I found the contact surface of the fuse box power tap had oxidized - it became quiet immediately after sanding. For cars with modified audio systems, pay extra attention to amplifier interference - I recommend adding a ferrite ring on the navigation power cable. If you really can't find the cause, just spend fifty yuan to buy a power filter and connect it - much easier than rewiring.
The buzzing noise is indeed annoying; my car had the same issue before. Here's a simple three-step solution: First, unplug all aftermarket USB devices—sometimes phone chargers are the source of interference. Then, tap the side of the dashboard; if the sound changes when you tap, it's likely a loose wiring harness. Focus on checking the gateway plug under the steering wheel, as many cars route wiring there. In one case I saw, water seeping into the wiring harness connector during window tinting also caused electrical noise. If you're fixing it yourself, prepare a socket wrench and a multimeter. If the voltage fluctuation at the head unit interface exceeds 0.5V, it indicates unstable power supply.
