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How To Fix Car Stereo That Turns On and Off Repeatedly

Car audio systems are highly complex systems with so many components and wires, and this makes them prone to failing in different ways as any of these components and wiring can stop working unexpectedly. For this reason, their problems are often difficult to root out.

So while head units are just one component among many, the problems they can introduce are vast and varied.

One of the most common problems with car stereos is turning on and off repeatedly. When this happens, the problem is most likely in the wiring. However, depending on how the head unit is failing to operate, you could also be dealing with a blown speaker, bad speaker wires, impedance mismatch, or even a faulty head unit.

Here we look at some of the most common causes of car radio turning off and back on, and also provide some handy tips to resolve the problem with the minimum amount of inconvenience.

What Causes a Car Stereo to Turn off and Back On?

Given the complexity of car sound systems, countless things can go wrong and lead to problems like car stereo cutting out when the volume is cranked up, car stereo shutting off completely while you’re driving down the road, or car stereo having power but no sound from speakers. But, while each situation is different, the following are some of the most common causes of a car radio that keeps turning on and off by itself.

1. Loose pigtail connector

If your head unit is turning on and off while you’re driving, it’s highly likely that there’s a problem with its wiring. This is especially true if it loses power and its display is shutting off.

That said, the very first thing you need to check when this happens is the pigtail connector (which is also referred to as wiring harness). The latter offers connections for the power and speaker wires. But, it can also include connections for the new stereo’s ground and illumination wires.

To check the pigtail connector you will have to remove the head unit to gain access to the wiring. Once the head unit removed, make sure the pigtail connector is seated properly in the head unit.

If, for some reason, the pigtail doesn’t clip in securely, you’ll have to replace it. Furthermore, if your particular installation has some sort of adapter that sits between the head unit and the factory wiring, unplug the entire thing and plug it in back again to ensure that everything is making good electrical contact.

2. Damaged or loose car stereo power and ground wires

Another very important thing to check is the power and ground wires. When a power or ground connection is loose, the car stereo will cut out randomly especially when volume is turned up. This is because driving over speed bumps or rough terrain can cause the connection to break or short. In some cases, the power will return when the car stops, or with further jostling, making the radio only function sometimes, or turn back on as suddenly as it turns off.

To track down a loose power or ground wire, it’s recommended to start at the back of the stereo. This is because sometimes when you’re dealing with an aftermarket head unit that wasn’t professionally installed, you’d be surprised to find out that the wiring wasn’t done right and that the connections are loose or poorly-made. This holds true especially when the vehicle was bought used.

If everything checks out okay there, you’ll have to further expand your search. Here are the basic steps to follow to ensure the wires are intact and that the head unit is properly grounded.

  • Remove your car stereo.
  • Thoroughly examine the wires on the back of the stereo.
  • If any of the wires have come loose, frayed, or corroded, you’ll need to cut, strip and crimp or solder them back in place.
  • Follow the ground wire from the back of your stereo to where it’s connected to your vehicle.
  • If the ground wire is loose, tighten it. If it’s corroded, clean the corrosion, and scrap any paint until you see the shiny metal and then bolt it back in place securely.
P.S: When grounding a car stereo it’s crucial to provide the head unit with the same ground reference that your amplifier have. Because otherwise, you’ll be dealing with ground loop problems such as noise, interference, whining…etc.


If, while inspecting the back of the head unit, you find out that the power, the ground and the speaker wires were soldered, connected with butt connectors, or were simply twisted together and taped, that could be the culprit. Poor soldering, or loose butt connectors, can also cause a momentary loss of power or ground.

3. Blown fuse

Fuses are electrical sacrificial devices used to protect much more expensive electrical components in the event of excessive current flow (overcurrent).

Most aftermarket car radios come with a built-in fuse that’s typically located on the back side of the receiver. Factory stereos’ fuse is most often located in your vehicle’s main or accessory fuse block.

Although fuses are typically either good or blown, there are some situations where a fuse can be partially blown but still maintains electrical contact that breaks sporadically, making your car stereo give up the ghost.

That said, make sure to check your head unit’s fuse. If you notice that it’s blown, then that may be the cause of your problem.

Using a multimeter is the best way to check if a fuse is blown or not. This is because sometimes a fuse can bit the dust in such a way that it is difficult to tell one way or the other simply by looking at it.

4. Loose faceplate / dirty connectors

Most aftermarket head units come with a detachable faceplate to deter theft in case you are in a questionable neighborhood.

Now, behind the removable faceplate there are some metal connectors that connect to the base unit. Hence, if the front panel is not pushed in correctly and clicked in, it’ll cause intermittent connection, and the car receiver may shut off or lose power. Which in turn will make your sound cut off, or make the head unit turn off randomly when you’re driving down the road.

That said, always ensure that the connectors aren’t dirty, and that the removable faceplate is fully pushed onto the base unit and that it’s clipped in firmly.

5. Head unit in protect mode

If your car stereo lights up but but no sound is coming out of the speakers, then you’re dealing with a different issue. In this type of situation, it’s very likely that the head unit is in “protect” mode.

A head unit is protect mode will “turn on” in that the display will light up, but it will only show a message such as, “Protect,” “Service”, and fail to operate.

Protection mode is essentially just a shutdown state that car stereos and amplifiers can go into when something goes wrong. The main purpose of this shutdown state is to prevent serious damage to the head unit or other components in the system.

Car stereos go into protect mode for a wide variety of reasons including but no limited to:

  • Impedance mismatch (head unit overloading)
  • Wiring problems
  • Bad ground
  • Faulty speaker
  • Loose/damaged speaker wires
  • Internal faults
  • …etc.

6. Faulty head unit

If everything checks out okay, but your radio is still misbehaving every now and then, then there’s good chance you’re dealing with a faulty head unit.

A faulty head unit should be returned to the manufacturer for repairs if it’s still under warranty, or find a local stereo repair shop that can diagnose the problem for you. With any luck, you’ll be jamming again in no time.

Bottom Line

There’s nothing quite as frustrating as having your music interrupted by intervals of complete silence. If you’ve ever had a similar issue, you know how annoying it can be. You want it fixed immediately.

Since each car is built differently and has a different car stereo system, it can be hard to tell where the problem might be lying exactly without having some information about you overall sound system. However, the things we listed above should help you fix most problems of this kind for the most part.

If you couldn’t fix the problem yourself, feel free to contact us. We would love to see how we can help out!

Alex Brown

Hey There, my name is Alex Brown, I'm an LA-based sound engineer with over 10 years experience installing, troubleshooting, and repairing commercial, automotive, and household sound equipment. I've installed highly competitive car audio systems, and everything from navigation systems to full car stereo systems, remote starters, alarms and beyond. I enjoy creating solutions and simplifying everyday needs. I also love helping people get great sounding gear, thereby, saving the world from bad sound one customer at a time.

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