• Fri. May 27th, 2022

Two Simple Checks to Diagnose Power Faults with Car Stereos 

ByTahlia Mills

Jul 16, 2018
car audio speaker

Car stereos are normally very well designed and reliable pieces of equipment, but there are always times when faults occur and units develop problems.  In these situations there are often some simple causes that most people should be able to check themselves as well as a range of possible faults that will result in more complex diagnostics being required.  Of the possible faults you could encounter, having a stereo that will not power on is by far the most common and consequently often the simplest to fix.  So if you find that your stereo is misbehaving, and you have exhausted the basic checks discussed below, then you really need to find a reliable car audio repairs specialist to ensure that it is restored to working order safely and quickly.

car audio systemConnections

If you have installed a new stereo or added anything new to the system, then this should be your first port of call when trying to diagnose any problems.  If the system will not power on after added something new, then removing the new item and retesting will let you know if the addition is the problem or not.  If you have installed a new system, then checking all of the connections are firmly in place and that the correct sockets have been used is vital to avoid power issues and potential damage.


If you are certain that the stereo is connected properly or that it has not been replaced, then the next things to investigate are fuses.  There can be several different fuses in play with a car stereo system and they will each need checking to verify if they are the cause of your power loss or not.  The first place to check would be the stereo itself to ascertain if it has an isolator fuse or not.  Not all systems will have one and the manual is normally a good place to check for this information, but if there is one in your stereo then it will probably be a lot more sensitive that the more general ones found in the car and should be checked.  Fuses can be checked either visually, as if they are glass you should be able to see a noticeable break in the filament.  If you cannot see a break or the fuse is not glass then a multimeter is required to test the fuse for continuity.

car audio

If the system fuse is ok or not present, then you need to progress to checking the cars primary and secondary fuses for the voltage circuits the stereo is using.  This is usually the 12v circuit but systems will differ and for safety you should always check the cars manual for the correct process of testing its fuses as it might be necessary to disconnect the battery.  Above all else it is important to remember that when working with electricity you should always air on the side of caution and if you aren’t sure about what you are doing, don’t attempt it and get a professional to look instead.