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It is not uncommon to have to replace a car battery every 3-5 years if not sooner and after doing so, the car radio (head unit), can fail to start, freeze or reboot continuously after the battery has been replaced.
While the fixes for the car radio can vary from one car make or model to another, in this post, I’ll share some tips that can help you fix the car radio should it fail to work after a battery change.
I’ll also explain why the radio may fail after a battery change, and also share tips that can help you avoid both the loss of radio memory settings and the failure of the radio to work after replacing the car battery.
Why Your Car Radio May Not Work After a Battery Change
The car radio may not work after a battery change for several reasons.
For example, some radios require that a security code be entered before they resume working as a security measure by the manufacturers to discourage thefts of the head units.
Other radios may suffer from firmware related problems that show up as a frozen screen as an example, that require the radio to be reset before it can start working.
Read on to learn the different fixes you can implement to get your car radio working again depending on the nature of the problem it is facing.
What You Can Do if the Radio Fails to Work after a Battery Change
Here are a few fixes that you can try if your radio does not work after a battery change depending on symptoms faced.
#1. The radio does not power up i.e. the display does not light up at all.
Fix: When this happens, check that the fuse(s) protecting the cabling supplying power to the radio are intact.
You may have to pull out the radio to access the fuse.
There’s usually a fuse box located on the co-driver side near the battery under the hood.
Confirm that this and the fuse at the back of the radio (if present ) has not blown.
If the fuses are intact, disconnect the battery again for an hour or so to allow whatever power may still be in the radio to drain then connect the battery cables again.
If this does not work, you may have to contact the dealer for assistance.
#2. The radio powers up but goes into SAFE or LOCK mode, requiring you to enter a security code for it to work properly.
Fix: You may be able to find the car radio security code from the car radio manufacturer website, the vehicle log book or from the car dealer.
#3. The radio cycles on and off repeatedly. The car radio screen may light up, showing “loading” or “welcome” or other wording only to power down and start again.
You’ll likely need to reset the radio.
How to reset the car radio.
Fix: There is usually a specific sequence of actions that can work to break the continuous reboot. Consult the radio’s service manual or dealer on how you may be able to break the reboot cycle.
For example, in the RAV4 2020 model, the manual specifies thatapply the parking brake first.
Then shift the gear to the reverseposition for position for 5 minutes before shifting back to parking after which the radio should power up as normal.
#4. The radio freezes on booting up. You’ll likely need to reset the radio.
How to reset the car radio.
Fix: Try disconnecting the car battery terminal for an hour or so. Make sure the radio is completely off. This drains whatever energy may still be stored in the car radio electronics. Reconnect the car battery terminals again.
Sometimes, regardless of what you do, it may not be possible to get the radio to work again because of damage to the internal module(s) or corruption of firmware.
When the firmware is corrupted, the screen can stay blank, freeze and remains unresponsive regardless of which button you press.
Consult the car dealer. Beware of the diagnostic and repair costs and compare them with purchasing a new aftermarket radio as a replacement.
Check if it is worthwhile getting a new unit with warranty or investing in repairing the faulty unit that may fail again shortly after.
#1.Can you Reset a Car radio without a Code
Yes, some car radios can be reset without the need for a code. Consult your car manual to check whether this is the case. Check here for steps you may be able take to reset the car radio.
How to Reset Car Radio that Does not need a Code
As a general time, you can try powering down the radio completely by disconnecting the battery terminals from the battery to allow the change in the radio to drain completely.
You can leave it disconnected for an hour or so.
Additionally, some car radio have specific reset sequences. Check the car radio owner manual or website for the reset sequence. You can check our there car radio reset sequence for the RAV4 2020 as an example.
How to Stop the Car from Losing Memory Settings
You may be able to stop the car radio from losing its memory settings by first connecting the battery terminals to a car trickle charger (with the battery still connected).
Next, disconnect the old battery (while the trickle charger keeps the car electronics powered and their memory settings intact).
Lastly, connect the new battery securely (make sure you do not reverse the terminals) and then remove the trickle charger connections.
Hope this little trick saves you time that you’d otherwise spend programming your car radios stations and other settings. Thanks, @Selinger from RA4 World.
# 2. Use a car battery memory saver
Alternatively, you can also use a memory saver. It has a cigarette lighter plug and supplies power to keep the memory settings intact when you replace the car batteries.
You may also be interested in this post: How long your car battery lasts with the radio on?
If your car radio fails to work after a battery change, as first step, try disconnecting the car battery terminals for an hour or so to allow whatever charge may have built up in the radio to drain completely, and then connect the battery again.
Additionally, some car radios have specific reset sequences. Check the car radio owner manual or website for the reset sequence.
You can also contact the dealer or manufacturer for support. Beware, some car radios can still fail to recover so be open to the idea of replacing with a new one.