QuestionI just a new radio/CD for my maxima. Car have bose.It had been install by my self. And I follow all instruction to the "T". Got the radio working and all speaker working. But not the rear woofer. I had some one look at it in a sound shop. they redid a few things. But still no sound.All amp and speaker work and get sound. But the woofer will not. I call the shop around the area and no one can not tell me anything I already knew. Can you help.
AnswerHi Luis,
I don't think I can help very much without being able to look at the car and do some testing. I can't tell you why your amplified subwoofer isn't producing any sound, but I can tell you how to test it.
Your car's Bose system includes two amplifiers. One amp is mounted under the rear deck, and runs the front and rear speakers. The other amp is just for the subwoofer, and is mounted to the sub. The subwoofer amp gets an audio signal from the front/rear amplifier, so if you've bypassed the factory amp (connecting all your speakers directly to the new head unit) then the subwoofer amp won't get a signal.
If the main amplifier is still running all the speakers, you can test the wires at the sub amp to see whether the amplifier is working or not. Unfortunately, I don't have a wiring diagram for the sub amp, but I know a few of the wire colors, and the rest should be fairly easy to figure out.
First, there will be a pair of signal wires coming from the main amp. These wires will be black and white. When the system is playing, these wires should be carrying a low-level audio signal. You can test this using a multimeter with an AC voltage setting; if there's an audio signal present, you'll see an AC voltage reading that increases and decreases with the music volume.
There will be a pair of wires running from the subwoofer amplifier to the subwoofer. Since the amp is mounted right on the sub, the wires won't be very long, but you should be able to test them. These test the same way as the low-level signal wires. If you see AC voltage on these wires, but the sub isn't playing, then the sub must be defective.
The sub amp will also have an activation wire. This is a wire that should have 12 volts whenever the head unit is switched on. The wire color should be green with a white stripe. You can test this with a multimeter set for DC volts; the wire should have 12 volts with the radio on, and 0 volts when you turn the radio off.
Finally, there should be a power wire and a ground wire at the sub amp. You can use the DC voltage setting to see if the amp is getting power.
Depending on what's wrong, there may be various ways to fix it; for example, if the sub amp isn't getting an audio signal input, you may be able to connect some RCA cables and run them directly to your new deck's RCA subwoofer output. If the amp isn't getting power, you should check the vehicle fuses. If there's no voltage on the activation wire, you might be able to tap the main amplifier's activation wire to also supply the sub amp. If you find that the subwoofer is defective, however, you'll probably need to buy a replacement sub.
Hope this helps!
Brian
