HU Power Problem
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=83832
Printed Date: July 05, 2025 at 5:42 AM
Topic: HU Power Problem
Posted By: hammy2000
Subject: HU Power Problem
Date Posted: October 07, 2006 at 12:55 PM
I just installed my new Alpine CDE-9846 hu and im having a problem. Sometimes, the HU doesn't turn on, and when it does turn on, it will only play at low volume levels. Whenever i turn it up, it just shuts off and resets. Sometimes it will play just fine at high volume, but then it'll randomly turn off again. Also, whenever i turn the car off all the settings on the deck reset to default. I was told that the hu isn't getting enough power and that i need to run a direct cable from the hu to the battery. If this is true could you please give me some directions on how to do this. The hu i used before was working fine, it was only when i installed this one that it started acting up.
I have a '99 Corolla with 4 75w rms orion coaxial speakers and a 240w bridged alpine amp/300w jl sub if this helps.
thanks
Replies:
Posted By: DYohn
Date Posted: October 07, 2006 at 1:10 PM
Could also be simply poor quality HU connections (i.e.: loose) and if the system is shutting down at high volume the most likely culprit is overloading due to too low impedance speakers or bad connections to your amp. ------------- Support the12volt.com
Posted By: hammy2000
Date Posted: October 07, 2006 at 3:26 PM
I checked all the connections and they're all very secure. I don't have the acc and constant reversed either. Could it be that since i have the amp remote turn on lead and the acc from the hu spliced into the same wire?
Posted By: DYohn
Date Posted: October 07, 2006 at 5:17 PM
hammy2000 wrote:
Could it be that since i have the amp remote turn on lead and the acc from the hu spliced into the same wire?
Huh? Are you saying you connected the HU remote turn-on to the ACC power signal from your car? This is wrong and may damage your HU. The ACC input for the HU is connected to the ACC signal from your car, and the remote turn-on lead supplies power from the HU to your amp to activate it. These should NOT be connected together! Read your owner's manual... ------------- Support the12volt.com
Posted By: i am an idiot
Date Posted: October 08, 2006 at 10:02 AM
[QUOTE=hammy2000] I was told that the hu isn't getting enough power and that i need to run a direct cable from the hu to the battery. If this is true could you please give me some directions on how to do this. The hu i used before was working fine, it was only when i installed this one that it started acting up.
Hammy you have been correctly informed about the power wire needing to be run to your battery. not sure of the model numbers but I do know that some alpine decks do require a wire run to your battery. ****** I have not installed in years so I am not familiar with your car and where you would go through the firewall but maybe some of the guys will notice this new post and have some good info for you. ******* Just remember when attatching the wire to your battery you MUST attatchatch an In-Line fuse holder with a 15 amp fuse directly to your battery and then connect a 12 Ga. or larger wire to this and run this to your radio
Posted By: sparkie
Date Posted: October 08, 2006 at 11:34 AM
What you need to do is use a digital volt meter. Set the meter to a DC voltage scale and put the black probe on the black wire at the radio. Put the red probe on the yellow wire at the radio. With the ignition off, you should have battery voltage (at least 12 volts). Next turn on the ignition. Your voltage reading shouldn't change that much, maybe half a volt. Next place the red probe on the red wire. You should again get around 12 volts. Next start the car. Re-check the voltages on both the yellow and red wires. They should be slightly higher (13 - 14.5 volts). If you don't get these readings, then you have a problem with either your power sources or your radio ground. If you do and still have a problem, then disconnect all other wires except for the red, yellow and black wires. If the head unit still cuts out you need to have it repaired.
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sparky
Posted By: i am an idiot
Date Posted: October 08, 2006 at 11:40 AM
If you are going to take sparkies approach don't forget to make these checks with the volume turned up to a moderate level you will not achieve any voltage drop without trying to pull any current through the wire I thought we were looking for advice in running a wire to your battery as required by some alpine Decks Guess we are not gonna get help from here
Posted By: geepherder
Date Posted: October 08, 2006 at 1:20 PM
I've never ran a lead to the battery, even on the Alpine models that say they "require" it, and have not had any problems. I've gone to the ignition harness to get power before, but only because of problems with the vehicle's wiring, not because it was an Alpine.
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My ex once told me I have a perfect face for radio.
Posted By: hammy2000
Date Posted: October 08, 2006 at 10:35 PM
ok thanks, I'm going to try to run a line to my battery and see if it works.
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