If you’re a car audio enthusiast, you know that your amp is a critical part of your system. But what do you do when your amp goes into protection mode? Let’s find out.
To get an amp from the protected mode:
- Turn it off to prevent further damage and let it cool down.
- Check that all wires have the correct sizes and that all connections are tight and secure.
- Check if the impedance load matches between the amp, speakers and subwoofer.
- Reset the amp’s gain and set it from scratch.
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Tip: When checking the amplifier, you should not rely just on the visual check.
For me, the best tool for car audio is the multimeter that you should use every time to check the wiring, impedance or voltage in the car’s installation.
Although there are many available, my favourite is the AstroAi 6000 (link to Amazon), which in addition to all the electrical checks, also allows me to check the surface temperature, which is critical to find any faults and overheating car audio elements.
In this article, I will show you how to get your amp out of protection mode and make it function in no time.
What Is Amplifier’s Protection Mode?
An amplifier’s protection mode is a safety feature that kicks in when the amp is overheated, overloaded, or short-circuited. When this happens, the amp will shut down to prevent damage.
Amplifiers are built of many components that are difficult to replace and expensive.
Most critical are transistors, without which the amp will not work, and the protection mode prevents them from overheating and burning out.
If your amplifier goes into protect mode frequently, it is a sign that something is wrong with the sound system, and you have to troubleshoot the problem and fix it immediately.
It is better to fix the issue earlier than replace the whole amplifier later.
Most modern amplifiers have a protection light on the amp that switches whenever the system detects a problem. If it doesn’t have a light, you must go through the manual to determine if the amp is in protection mode.
The power LED indicates the amp’s status. When the amp is working ok, the light is green, but for the protection mode, it can be either orange or red, so if you see those colours on the amp’s body, you should start the troubleshooting.
How to Get Your Amp Out of Protection Mode?
Now that you know how to figure out if the amplifier is in protection mode let’s move on to how you can get it out of this state.
#1. Turn the Engine Off.
Turn off your car’s engine and remove the key from the ignition.
This will prevent any electrical surges from damaging your amp when you connect it again.
#2. Disconnect Speakers
Disconnect all speaker wiring, including the RCA wires from the head unit to the amp. An amplifier should stay connected only to the power, ground and remote leads.
#3. Turn the Engine and the Stereo On.
If after turning the amplifier on, it works, it means that one of the speakers (or all) caused the problem or short circuit.
For example, one of the speakers may be blown and has to be replaced.
#4. Check All the Speakers.
If one speaker is either blown or grounded to a metal part of the body, the amp can see this connection and quickly overheat, so to prevent damage, it goes to the protection mode.
To check if the speaker is blown, use the multimeter and set it to ohms.
Take the probes and stick them to both speakers’ wires. If the impedance is shown within the speakers’ limits (2-4 ohms), the speaker is good, but if the reading shows much higher or the impedance is unlimited, the speaker is blown and must be replaced.
#5 Check the Amplifier’s Temperature
If you feel that the amp is already too hot, it can quickly overheat.
When the amp is overheating, there may be many reasons, like overload from the speakers, blown or grounded speakers, poor power or ground connection, or insufficient airflow.
Some amps produce a lot of heat like A-class models, so with those, you have to be careful and provide additional ventilation or even install extra cooling fans.
If the amplifier is too hot to keep your hand on it, it is overheating. Let it cool down for a few minutes before further troubleshooting the problem.
#6. Check the Ground Connection
Also, if the ground wire is not connected correctly, it can cause all sorts of problems for the amplifier, including entering protection mode.
You should always connect the ground wire to a clean and unpainted metal surface on the car body.
If the ground connection is not solid, then this could be the reason why your amplifier keeps going into protection mode.
I had this problem many years ago when I chose the wrong grounding point with high resistance, so before deciding about the grounding point, check it with the multimeter.
The measured resistance should be close to 0 ohms, and if you measure several potential grounding points, pick one with the lowest resistance.
#7. Check the Power Wires.
To function correctly, amplifiers need thick power and ground cables tightly connected.
If either of the cables is too thin, the amp will shut down and enter protection mode, especially when you play hard-hitting bass tones.
Also, if the amp doesn’t receive the power it needs because of the wrong size or loose wires, it will fail to turn on or stay in protect mode to prevent damage, so make sure none of the cables is loose, corroded, or shorted.
#8. Check Impedance Load
If the impedance load is too low, it will cause your amplifier to shut down and go into protection mode. Therefore, the impedance of speakers should match the rating of your amplifier.
For example, if you have a 4-ohm amplifier, I recommend using 4-ohm speakers.
If you use 2-ohm speakers with a 4-ohm amplifier, the power demand from the speakers will double, and in effect, the amp can quickly become overloaded and enter the protection mode.
To fix this problem, you need to use speakers with a higher impedance rating that matches the rating of your amplifier.
Ensure all speakers and subwoofers match the impedance and the amp can handle their total load.
#9. Reset the Amp’s Gain
If the amplifier’s gain is set too high, it can cause it to go into protection mode. The best way to fix this is to reset the gain and set it from scratch.
Adjusting the gain will result in a clear, rich sound free of background noise.
Though the gain setting doesn’t directly cause a protection mode issue, if the gain is set too high, it will result in distortion of sound or speaker damage.
And that, in effect, can turn the amplifier into the protect mode.
So, starting with a lower gain setting is always better and slowly increasing it until you reach the desired sound level.
What Causes an Amp to Go Into Protection Mode?
There can be many reasons for an amplifier to go into protection mode.
The most common reason is an issue with the speaker impedance. If the impedance is too low, it can cause the amplifier to overheat and go into protection mode.
Other common causes include a power or ground wire not connecting correctly or an insufficient airflow around the amplifier.
There are many reasons an amp could go into protection mode. However, here are the most common ones:
#1. Internal Failure:
Internal failures are internal amplifier problems with the circuitry that can cause the amplifier to go into protection mode.
Internal failures are often caused by a manufacturing defect or by damage from a power surge.
If an internal failure like malfunctioning transistors can cause the amplifier to go into protection mode, the only way to fix it is to have the amplifier repaired by a professional or, in most cases, replaced.
#2. External Failure:
This could be caused by any car audio elements that are not functioning correctly or are damaged.
External failures are often caused by a loose wire, a short circuit within the installation, or even inside the head unit.
If you have a loose wire, it can cause the amplifier to overheat and go into protection mode. To fix this problem, you must find the loose wire and tighten it.
Overheating directly affects the functioning of the amplifier.
Especially if you have an amp installed in a tight spot with poor airflow, the thermal overload can trigger the amp to go into protection mode.
Overheating can be caused by several things, including a loose wire, bad airflow, or a low impedance load.
The dangerous thing about the overheating amplifiers are their plastic components that can melt inside and cause severe internal damage, or worse, a fire.
So, if you have an overheating amplifier, it is crucial to find the cause and fix it immediately.
#4. Impedance Mismatch:
The impedance of your speakers should match the rating of your amplifier.
As I mentioned earlier, if the speakers’ impedance is too low, it forces the amplifier to work harder and, in effect, to overheat and go into protection mode.
#5. Overwhelmed Circuits:
Overwhelmed circuits are often in systems where the amplifiers are not strong enough for powerful subwoofers.
A plugged subwoofer that demands amplifiers to work too hard at the high volume overwhelms the circuits and often causes the amplifier to go into protection mode.
To avoid this problem, ensure that your subwoofers and amplifiers are well-matched.
Choose an amplifier that can handle your subwoofer’s power demands. In the best case, the amplifier’s RMS should be between 1:1 to 2:1 to the subwoofer’s RMS wattage.
In other words, if you have a 300W subwoofer, the amp’s RMS should be between 300 and 450 Watts.
How to Troubleshoot an Amp That Keeps Going Into Protection Mode
If you do not have an experience with the car audio system, troubleshooting the amp may be a complex task, and you may need to ask a professional for support, but there are a few things you can do by yourself:
#1. If your amplifier went into protect mode the first time you turned it on, this gives us an insight into why it was malfunctioning.
For example, it could be that the amp is installed incorrectly or one of the speaker wires is loose.
- Check all the power cables and ensure the amp is not in physical contact with the metal part of the vehicle.
- Next, examine all the wires and make sure they haven’t shorted or corroded.
- Finally, check if the remote wire has power.
#2. If your amplifier is going into protection mode frequently, there may be something wrong with the amplifier itself.
In this case, you need to take it to a professional or the place where you bought it and have it checked.
#3. If the amp goes into protect mode on a bumpy road, you may have a loose wire.
This automatically shuts the amp down and puts it in protect mode. To fix this, check all the wires’ connections and make sure they are tight.
#4. When you’ve been playing music for hours, and the amp suddenly goes into protect mode, it is likely overheated. So the first thing you have to do is to let it cool down for a while.
If the amp is in the trunk, open it and let the fresh air cool the amp down.
It is also possible that car audio circuits are overloaded. Check if the subwoofers and the amp have matching power and the exact impedance load.
To take the amplifier out of protection mode, you need to find the cause of the problem and fix it.
Overheating, wrong impedance, overwhelmed circuits or bad wiring are the most common reasons an amplifier enters protection mode.
If the amplifier goes into protect mode frequently, you need to take it to a professional to further check the internal circuits.