What would cause a car radio to not turn on?
If your car stereo has power but won’t turn on, the most common reasons are blown fuses, faulty wiring, and dead batteries that activate the anti-theft modes of the car. You can fix this problem quickly by doing some simple checks on your car’s fuses, pigtail connector, power at the head unit, and protect mode.
Table of Contents
To figure out why your car radio won’t turn on when it has power, you’ll need to look at each of these possible causes one at a time. In this post, we will go through all possible causes & the related fixes for the car stereo not turning on when it has power.
The Protected Mode May Have Been Activated
When there is a power outage, some audio units feature an anti-theft protection function that is affected. The reasoning behind this is that if the audio device is stolen, it will be rendered unusable.
You should see a different message on your car audio if it has an anti-theft protected mode. It should either ask you for a code or not work at all. You’ll need to input a code or go through some troubleshooting procedures to fix this. For guidance, you should check the manufacturer’s instructions.
However, the problem could be something else if the screen is completely blank and your stereo does not have an anti-theft option.
You May Have a Blown Fuse
The next step is to examine the fuses after you’ve confirmed that the machine is genuinely failing to power up and hasn’t gone into an anti-theft mode. You’ll need some simple car diagnostic instruments at this point, such as a test light and a multimeter.
You’ll need to check one or two fuses on the majority of car stereos, and you might also have auto amp fuses and other associated parts in the mix. One will be found in the main or auxiliary fuse block of your car, and it will be clearly labeled.
You can physically check an automotive fuse or utilize a test light or a multimeter to test for power on each side of the fuse. If you have access to a test light or a multimeter, it is the better option because a fuse can fail in such a way that it is hard to identify whether it is good or bad just by looking at it.
Some head units have fuses built into them on the rear end, while some installations have extra in-line fuses on the power cable or wires. If any of these fuses are damaged, your car stereo may not turn on, so replace them to see if it solves the problem.
The Pigtail Connector May Have Malfunctioned
To obtain access to the wiring, you’ll need to detach the head unit before continuing with the diagnostic process. With that in mind, double-check that the pigtail connector is properly positioned in the head unit. If you have any concerns regarding the pigtail, you can detach it and replace it to ensure its proper seating.
The Power at the Head Unit May Be At Fault
Most automobile radios have two wires for power: one that is constantly hot and powers the memory, and the other that is only hot whenever the ignition key is turned on. The radio will not function properly or at all if these power lines are reversed.
If there is power at the fuse block but no voltage at the head unit, you are most likely faced with a broken wire, and you will need to trace the power wire down to the source to find and fix it.