QuestionQUESTION: I have a clarion dxz865mp head unit installed in my car. If I turn it up to a certain volume the head unit shuts down, but if I use the amp cancel feature I can crank it as loud as I want and it wont power down but only my subs are kicking, the speakers get no sound. So im thinking that my car has a stock amp and the head unit is pumping to much juice through it making it shut down. If this is so how can I disable the stock amp and power my speakers through the head unit since it has a 212 Watt MOS-FET Amplifier built in.
ANSWER: Hi Bill,
If you can tell me the year and model of your vehicle, I can provide a much more helpful answer.
I've never seen a case of a factory amp shutting down from too much input power. I think it's more likely that your head unit is already connected directly to the speakers, but there's either a speaker issue or a power supply issue that's shutting down the head unit. The amp cancel feature shuts off the deck's internal amplifier; this will cut off the power on the speaker outputs, so a speaker issue wouldn't affect the deck, and it will greatly reduce the deck's current requirements, so a problem on the deck's power supply wouldn't be as likely to cause a problem either.
When you say the deck is shutting down: is it shutting off entirely, with nothing on the display? If so, then it's likely that the deck is either poorly grounded, or has a problem with the (yellow) main power wire. Or is the display still working normally, but you just lose the sound? In this case, there may be a shorted speaker wire, or the speakers may be too low impedance for the head unit.
If you'd like to follow up with the vehicle information, and a more detailed explanation of what the head unit is doing, I might be able to provide more information. Otherwise, all I can do is guess.
Hope this helps!
Brian
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QUESTION: The car is a 98 cavalier and when the deck shuts down it shuts off completely. It powers down completely as if you were to hit the power button, no display nothing, it just shuts off entirely then it pops right back on and unless I turn down the volume it will do it again repeatedly. This problem occurs at alittle over half of max volume anything else it plays fine but once you crank it up it just keeps shutting down until you lower it. The speakers in the car are aftermarket speakers not stock if that helps you figure it out. I appreciate your input and thanks for your responses.
AnswerHi Bill,
I've never seen a Cavalier with a factory amplifier, and it sounds very much like a power problem. Basically, when you're using the deck's built-in amplifier, it draws more current through the power line as you turn up the volume. If there's a resistance in the circuit, either on the main power wire or the ground wire, it will produce a voltage drop as the current increases. When the voltage drops too low, the deck shuts off. When it shuts off, the current flow stops, so the voltage comes up again and the deck turns back on, then the cycle repeats.
The main power wire for the deck should be a thick yellow wire, and the ground wire should be black. There will be a red wire and (possibly) a smaller yellow wire as well, but these wires don't carry a significant current load. If I were troubleshooting the problem, I'd use a multimeter to test the voltage at various points, to see if I could locate the trouble spot. If you're using an adapter harness to connect to the factory radio plug, you might try bypassing the harness connection, and splicing the radio's power wire directly to the factory power wire. You can do the same with the ground wire, or connect it directly to a metal point under the dash instead of using the ground wire in the stock radio plug.
Hope this helps!
Brian
