How to Fix Car Stereo When the Head Unit RCA Output Not Working Properly

Your car music system depends on a perfectly working pair of RCA outputs. If the head unit RCA output is not working, the entire system will malfunction. On the bright side, there are several ways to troubleshoot and fix a head unit RCA output not working.

If you want to connect an external car amplifier to your stereo, you must have a working head unit RCA output. This makes it possible for audio signals to travel to the amp and be converted into powerful signals capable of driving the car speakers. However, if the head unit RCA output is not working as it should, your music will not be amplified. Instead, you will only get low quality or no sound at all.

What Causes the RCA Output to Stop Working and How to Fix It

Before you learn how to fix a malfunctioning head unit RCA output, it is also essential to learn what causes the problem. This way, you can know how to prevent the problem from recurring. RCA outputs are exposed to several risks. While some are easy to fix, others may prove to be more challenging to deal with. Here are some of the reasons why your head Unit RCA Output not working correctly and how you can fix it.

1. Messed Up Socket Connection

The RCA is made up of several socket sets. If you are not familiar with these sockets, you may end up putting the right cables in the wrong socket or the wrong cables in the wrong socket. It would be best if you used specific sockets to connect the radio unit and another socket for connecting the amp to the systems.

To ensure you have a good connection, the stereo cables should be connected to the output sockets. These sockets are labeled intuitively as “audio out” or “sub-out.” If a wrong connection is causing the RCA output not to work properly, check the connection to ensure that it is in the right socket on the back of the wiring harness.

2. Manual Muting of Sub Level

Several aftermarket stereos have a setting or option that allows you to adjust the amount of output that goes into the sub-level of the amp. When the head unit RCA output is not working, you should also check if the sub-level is muted. This is a very common error. Many people accidentally mute the sub-level causing the bass to stop playing.

Therefore, before you look for a more complicated issue, ensure that the sub levels are not turned all the way down. If they are, adjust the levels to at least halfway to feed the amp with a strong signal at all times.

3. Internal Damages

Internal damages to the car stereo or amplifier can prevent the head unit RCA output from working as it should. This problem mainly occurs when the power cables are connected to both the stereo and the amp while they are working.

This connection alters the current flow and can cause thumping sounds whenever you turn on the system. The thumping sounds can also result in damaged diodes or resistors in the system.

4. Messed Up Cables

Broken or bad cables can easily ruin your stereo. Bad cables cause several problems in the system, including low-quality audio, unclear sounds and a malfunctioning RCA output. Though uncommon, cables can go bad if the solder at the end of their connectors is broken due to excessive fiddling, pulling, and tugging.

If the cables are broken, the connection will not be complete, and this will affect the head unit RCA output performance. If that is the case, you will have to replace the cables. To get the most value out of your RCA cables, avoid fiddling with them and try not to unplug or pull them unnecessarily.

Keep the cables organized and ensure that the head unit is well ventilated because high temperatures can also cause them to wear out fast.

Testing the RCA Output Using a Multimeter

Testing the RCA Output Using a Multimeter

If the head unit RCA output not working properly, it is essential to test it with a multimeter. If the head unit RCA output not working properly, it is essential to test it with a multimeter. Doing this will help you know where the problem is more precisely. Since RCA outputs transfer output signals into the amplifier through the cables, they should be able to have an active signal.

To test the RCA output, you should first set the multimeter to read in volts and then turn your car stereo volume up. This will send a robust signal to the RCA, and the multimeter will be able to pick up the signal more easily.

To measure the ac voltage, place one probe on the center pin and the other on the outer ring. If the voltage changes on the multimeter’s screen, then the connection is normal, and the RCA output is receiving the proper audio signal.

Testing the RCA output with a multimeter will help reveal any problems with the signal reception and show how well the connection works. If that does not fix the problem, you might troubleshoot for other issues. For example, if you get no readings or readings in DC in the multimeter, a messed-up connection can be the cause of the problem.

You may also want to Learn: How to Test a Car Amplifier with a MultiMeter

Wrapping Up

There are many reasons for a head unit RCA output not working properly. Always look for the minor issues first before troubleshooting the entire system for deeper issues. Also, make sure that all components of the system including the wires and outputs are well maintained for good performance in the future.

Avatar for Jamie K. Martin

Jamie K. Martin holds a degree in Audio engineering from Husson University, Bangor. Martin spends most of his time testing and trying the technology he writes about to ensure that he provides first-hand information to our customers from all walks of life.

Leave a Comment