I tested my batery and the alternator and everything works great.

I do not have any amplifier connected it is just the stereo and four speakers. not big deal. i used to have an amplifier an a capacitor but because this problem i disconected until i fix it.

the stereo isn't actually too loud. when the volume is on 19 or more the stereo stop working(turn off) and it turn on itself in a seconds and it shut off unless i turn the volume down.

it happen with the car off or running it.

any idea what the problem could be?

Here is a video showing it.
http://www.youtube.com/watch?v=_FmWDifMYSs

Kenwood KDC-MP538U
Honda Civic 2001 EX
(sorry my bad English)

 

bum..

 

Seems like a loose connection somewhere inside the deck, probably the main power or possibly a short. It loses power for a second then it powers back up. Send it to Kenwood for repair, or take it back to the shop you bought it at and see if they'll hook you up.

 

the thing is that i tested with another stereo too and it happen the same thing. it took more time to turn off if the car is running but just for a few seconds more.

 

when i said that i tested the batery and the alternator i did with a multimeter. when the car is off the batery is on 12.65v and when the car is running it goes up to 14.50v that how i tested.

 

I would run a positive wire from the battery to the stereo and turn the radio up and see if it turns off. Keep the ignition wire hooked up from the factory harness/aftermarket adapter. If it doesn't turn off as listed above, you have a bad power wire somewhere in the line.

 

Ditto the above^^^ kind of.

Run a fused 12ga power lead from the batt. to behind HU and connect HUs 12V+ constant, [yellow] to it, don't forget to cap off the stock radio harness12V+ constant so it can't short out.

The above should be done even if it is not your problem, the stock 12V+ constant can not supply the current needed by the HUs built-in "high power" 4ch amp. the same goes for the stock ground lead, leave the HUs ground connected to the stock ground but add a 12ga ground lead from chassis of HU to cars chassis.

Of the above does not solve the problem, temporary connect the HUs 12V+ switched lead, [red] to the 12ga fused lead you ran for the HUs 12V+ constant, [HUs yellow and red leads together to the 12ga].
Before you do any of the above, change the stock radio acc. fuse, [in under dash fuse box] replace it even though it looks good. 94

 

Probably have a bad speaker or a shorted speaker wire making the deck overheat and go into protect mode. Unhook one speaker at a time and listen to music if it works fine with one particular speaker un hooked thats the problem speaker.

 

Although a possibility, I know of no HU that turns off anything but the amp when going into protection mode, the screen will stay on, for everything to turn off HU needs to lose it's acc. power, [switched power] although low voltage or current could result in a complete shutdown.

With that said, I do agree that when an amp shuts down, [even one built unto a HU] checking for shorts on the outputs is always a good idea, a common problem on Honda/Acura is when installing door speakers and mods have to be made and proper speaker mounting is not observed, [speaker terminal orientation] the speaker terminal(s) can short to the doors sheet metal and how badly the terminal shorts out will determine when protection mode "turns on" when amps output(s) gets hot enough a thermal breaker will open and cut power to amp, again, normally only the amp is turned off the HUs face plate would stay on. 94