Car Stereo / CD Player Draining Car Battery Reasons & Solutions

It’s the driver’s worst nightmare. You rush to the car, already late to an appointment somewhere. Somewhere you should have been minutes if not hours ago. Nothing must go wrong now, you think about all the traffic and hope for the best as you turn the key of your car to start it.

Then the sound you can’t believe you are hearing. Your starter motor is spinning, but there is not enough power to start the car.

This has happened to us all. Maybe we didn’t even have a place to be in a hurry, but whenever we are in the car to start it, we tend to need to go somewhere.

Power leakage, or devices that consume power from your car battery while it is not on and while it is not being recharged can cause these unfortunate events.

The most probable car power drainer is the car stereo. In this article, we’ll take a look at what could cause your car stereo or CD player, a device that should bring enjoyment to your trips, to become the giver of pain and money-sucking worry.

What Causes Car Stereo Or CD Players To Drain The Battery Even When The Car Is Off

Bad Wiring And Connections

Bad wiring and connection could be the main reason why your car stereo or car CD player drains your battery even while it and the car is off. There are some electronic components of the car stereo that could actually continue to drain power if connected to an active source of electricity. The manufacturer of car stereo players typically provides you with accurate wiring diagrams in the installation guides and manuals. If this manual and wiring guide was not followed during the installation, there is a high possibility that the CD player will continue to drain or suck out energy even while not in use.


As this is a mid-advanced electronics/electrical work, it’s best to leave this to the professionals if you don’t have an understanding in this field. Car electricians have tools and devices that can trace leaks in power and can get to the root of the problem quite quickly. Once they find the leakage, they are able to rewire the system in the correct way. They may also end up finding issues with the CD stereo player itself, in that case, they will inform you accordingly.

If you want to get your hands dirty, and you have a good grasp of DIY and a mid-high level of understanding in electronics/electrical wiring, there are endless videos and guides online that show you how to troubleshoot this issue. Your car stereo CD player also comes with multiple manuals and instruction guides that can be found online by searching for the model number.

A Faulty Stereo or CD Player System

Once your wiring is checked, and it all looks good, the very next step in the troubleshooting guide is to check the radio or CD player itself. If these devices are badly manufactured, they could be keeping some electronic components alive and training power even when switched off.


This is another case where a professional electrician could help. They will be able to exclude the car wiring as an issue and focus on the stereo/CD player. The stereo could be pulled out and tested individually to see if it’s actually training power even while turned off. If this is the case, then you typically have the option to upgrade to a different car stereo system if your car comes with the possibility to install an aftermarket one or for the electrician to make modifications to the power circuits.

Damage To The Wiring Harness

If there has been significant damage to your car’s wiring harness for the car stereo, which could happen during accidents or flooding of the car’s electrical systems, a short could happen which could cause leakage of power and drawing of energy from the car’s battery even when the car is switched off. This is 1 of the more rare occasions in which your car’s battery could be drained by the car stereo player, but if you find yourself in a situation where the harness can get damaged, like the ones listed above, then it could be the cause of your car’s battery going flat even without use.


The solution to this issue can be found by a professional car electrician. In most cases, damage to a wiring harness can be very difficult and time-consuming to trace.

Parasitic Draw Of Current

This is another culprit related to the bad wiring and faulty stereo reasons. There are some head units that keep drawing power in a parasitic way. This should not be the case with good working units, so this issue will have to be checked as well.

Non-compatible CANBus System

If the CANBus system of your car is not compatible with the aftermarket car stereo head unit, the wiring may not be correct even if the cables are plugged in right. In this case, you will have to take back the head unit for a replacement with another that is compatible with your car’s CANBus system.


If the issue is with your canbus system in the car, there is little that can be done to remedy it. You’d need to get a car stereo or CD player that is compatible with your specific wiring system.

Wrapping it all up.

So there you have it. There are many reasons why your car battery may be getting consumed by your car stereo and most of them are listed here above. Mind you, if you don’t have the technical expertise, it is always best to consult with a professional car electrician. because of the intricacies of the car wiring system, and the fact that it’s quite difficult to actually access the internals of your car’s dash, a professional will be required in most cases. The benefit of doing your own research beforehand is that you don’t go in blind. You will be able to understand and help with the troubleshooting.

Also, what the expert says will make sense and you won’t be taken for a ride or cheated of your money, especially if you go to an electrician you don’t know or trust.

Best wishes with finding and closing this power leakage loophole.