Radio not working and car not starting?

MRROYBH23

MEMBER
2017 HYUNDAI ELANTRA
2WD
AUTOMATIC
71,000 MILES

Jumped the car and it started and I then had the battery test and AutoZone said it was fine, but the display is black and radio not working. Try to start the car the next day and wouldn't start but had interior lights and headlights worked, jumped car again and it started. I went out 2 hours later and car wouldn't start again and still the display is black and the radio still not working.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
48,292 POSTS

When the car was running did you have any warning lights on in the dash? I am wondering if the alternator is working correctly. Also, I would clean the connections at the battery.

This guide can help:

https://www.2carpros.com/articles/everything-goes-dead-when-engine-is-cranked

If the BCM is not shutting down, it will drain the battery as well, but I am wondering if the battery is still bad and just tested good as a false positive. Is the battery original? If so, I would replace it anyway because they don't last longer than 5 years. Here is a guide to help and instructions below for your car. On a side note, the radio and display will only work if there is at least 12 volts in the system. You can check this by using a voltmeter at the battery which should read around 12.4 volts.

Here is a guide to help with that as well:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

Please go over these guides and get back to me. I also included how to check the electrical system for draw to help confirm the battery is the problem.

Images (Click to make bigger)