Question about Kenwood KAC-8401 Car Audio Amplifier

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Amp not powering up correctly.

I have a kenwood KAC-8401 amp that has worked well in the past. one day when i went to turn my car on it wouldnt power up at all so i checked all my fuses and they were good, so i checked my wiring and it was good. The amp now powers up but only puts on a red LED light when it should be blue.

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Re: Amp not powering up correctly.

Check transistor of the unit 1 or 2 tans. bad use a tester. the unit is overload protected. replace the deffecteve parts

Posted on Sep 19, 2007

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I have a kenwood kac-8452 4 channel amp that makes the speakers pulse after the volume gets turned up to 10. I also have a kenwood amp doing the same thing with my subs. any ideas?

Its not pulsing, its called clipping. The sound is being clipped due the amp being pushed past is power capacity and distorting the signal. This will damage your speakers very quickly. No amp should be turned more then 3/4 up. If its not loud enough you need to purchase a larger amp or be comfortable with the wattage it produces at 3/4 volume. You may also have speaker wires touching/crossed causing th issue.

Sep 10, 2009 | Kenwood KAC-8452 Car Audio Amplifier

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No sound

What brand of reciever are you using. Most pioneers have a floating signal ground and the shield of the input at the amp needs to be connected to chassi ground. Also if you had a previous amp failure and the power ground in your old amp opened the current to power the amp will flow through the signal ground of the reciever and burn the copper trace on the circuit board in the reciever. test this by connecting signal cable shield to car reciever chassi.

Aug 29, 2009 | Kenwood KAC-8401 Car Audio Amplifier

1 Answer

How can i power on without the cd player, just only aplimifer

Impossible. You have to have not only a power and ground supply. But without a remote wire the amp won't know that you are trying to power it on. The remote basically sends the power to the amp when you turn on your radio.

Jul 08, 2009 | Kenwood KAC-8401 Car Audio Amplifier

1 Answer

What does it mean when the power light blinks on the amp?

genrally kenwood amps are power hungry amps so after playing for a while if it doesnt get the amount of amperage to make it work it will shut down cus you car cant charge the battery long enough for the use of that amp so my idea is try a farad capacitor and see if that helps good luck

May 29, 2009 | Kenwood KAC-7252 Car Audio Amplifier

1 Answer

Kenwood kac-x1r flashes code e-03


Apr 16, 2009 | Kenwood KAC-X1R Car Audio Amplifier

1 Answer


Either can either do it yourself like the guy above or take it to your local car audio dealer :)

Upfront Audio

Apr 10, 2009 | Kenwood KAC-9152D Car Audio Amplifier

1 Answer

Kenwood KAC-8401 light goes from blue to red when turned on

Either the amp is ad or the sub got shorted? You can check itby disconnecting the Sub and seeing if the amp comes on blue then. If yes, then the sub is shorted. If no, then the amp is shorted. Also chck the voltage AT THE AMP. Make sure that it is above 12 Volts.

Larry T
Winona Lake, IN

Dec 29, 2008 | Kenwood KAC-9152D Car Audio Amplifier

1 Answer

My amp wont put out any sound

You need to confirm that you have a good ground, and 12v on the terminals of the amp.

With your multimeter set to DC volts, the black meter lead on the ground terminal of the amp and the head unit on (so the amp will have remote voltage applied), touch the red lead alternately to the B+ and remote terminals of the amp. If the voltage is below ~11 volts, you need to check the wiring feeding whichever line is too low.

Dec 26, 2007 | Kenwood KAC-8401 Car Audio Amplifier

1 Answer

KAC-8401 Shuts off Blue light still lit


You might want to turn your Gain setting down a little. Also Look to be sure you have enough air flow around the amp. If it cannot breath, the heat from the amp will build until it wigs out. Use your Ingenuity to get more air to the AMp.

Nov 05, 2007 | Kenwood KAC-8401 Car Audio Amplifier

1 Answer

Amp won't turn on don't know if amp is fried

Very possible that you have a blown power supply in the amp. If you are running a mono amp then there is a very good chance that you have loaded your amp with too low of a speaker impedence and fried the power supply and maybe the output section of the audio area. Hope this helps.

Mar 30, 2007 | Kenwood KAC-8152D Car Audio Amplifier

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