If your head unit turns on just fine, but you don’t get any sound from the speakers, it’s easy to jump to the conclusion that the speakers are the problem. However, the fact that the head unit is turning on doesn’t mean it’s working properly. Before you do anything else, you’ll want to:
- Verify that the head unit hasn’t entered an anti-theft mode that requires a car radio code.
- Check the volume, fade and pan settings.
- Test different audio inputs (i.e. radio, CD player, auxiliary input, etc).
- Test any onboard fuses.
- Check for loose or unplugged wires.
. In car audio systems that use external amps (both OEM and aftermarket), the amp is the most common cause of this type of problem, since the audio has to pass through it on the way to the speakers.
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In the process of checking out the amp, you will want to:
- Verify that the amplifier is actually turning on.
- Determine whether or not the amp has gone into “protect mode.”
- Inspect for loose or disconnected input or output speaker wires.
- Test both inline and onboard fuses.
Although there are many common car amplifier problems that you can identify and fix on your own, you may run into a situation where the amp seems fine even though it has failed. In that case, you may need to simply bypass the amplifier to verify that both the head unit and speakers are working, at which point you can either get by with your head unit’s internal amp or install a new aftermarket amp.
Checking Car Speaker Wiring
When you checked the fade and pan settings on your head unit, you may have discovered that they were set to a speaker or speakers that had failed and that you were able to get sound by moving to a speaker or speakers that work. In that case, you’re looking at a problem with your car stereo wiring or a faulty speaker or speakers.
Since speaker wires are often routed behind panels and molding, under seats, and beneath the carpet, it can be difficult to visibly inspect them. Depending on your situation, it may be easier to check for continuity between one end of each wire (at the head unit or amp) and the other end at each speaker. If you don’t see continuity, that means the wire is broken somewhere. On the other hand, if you see continuity to ground, then you’re dealing with a shorted wire.