Car auto radio Alpine CDE-170R no sound

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.

If you are unable to locate any issues with the head unit, then you will want to determine whether or not you have an external amplifier. 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. 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.

If your speakers are mounted indoors, then a common point of failure is where the speaker wire passes between the door and the door frame. Although door wiring harnesses are typically protected by hard rubber sheathes, the wires can still end up breaking over time due to the repeated stresses endured in opening and closing the doors. With that in mind, you may also want to check for continuity and shorts with the doors both open and closed. If you find that one speaker is shorted to the ground in that manner, that can actually cause all of the speakers to cut out.

Testing Car Speakers

Another way to test the speakers, and rule out bad wiring at the same time, is to obtain some speaker wires and simply run new, temporary wires to each speaker. Since this is only temporary, you will have to gain access to the speakers by removing door panels, trim, and other components, but you won’t actually have to route the new wires properly.

If the speakers work with the new wires, it’s a safe bet that your problem is with the old wiring, in which case routing new wires will fix the problem.

You can also “test” car speakers by unplugging the wiring harness from the head unit or amp and touching the positive and negative wires of each speaker, in turn, to the positive and negative terminals of a 1.5V battery.

If the speaker wires aren’t broken, and the speaker hasn’t totally failed, you will hear a slight pop when you touch the wires to the battery terminals. However, the fact that you can get a “pop” out of a speaker with a 1.5V battery doesn’t necessarily mean the speaker is in good working order.

If you end up ruling everything else out, and you really are dealing with a coincidental failure, then it's time to just replace your car speakers en masse. However, you should probably make sure that they weren't blown out by someone cranking up the stereo.

This may also be a good time to think about upgrading your car stereo as a whole, although selecting some good aftermarket speakers to replace the blown factory units can actually help a lot by itself.

How Can You Tell If Car Speakers Are Blown Out?

It's pretty easy to tell when car speakers blow out if you're there when it happens because you'll immediately notice that they stop working or no longer sound normal. If it happens when you're not around, and the guilty party isn't willing to fess up, verifying blown speakers takes a little work.

The surest way to test whether car speakers are blown out is to disconnect the speaker and check for continuity. If there isn't any continuity between the speaker terminals, that usually means it's blown.

Power IC Off? Check. It shuts off the internal amp.