Symptoms
- No sound plays through the aux input even with source selected
- Sound only comes through one side (mono instead of stereo)
- Sound is scratchy or cuts in and out when the cable is wiggled
- Aux worked before and degraded gradually
Likely causes
- CommonAux cable not fully plugged inA cable that's slightly out can fail to make a full connection, especially with certain phone cases.
- CommonWorn or damaged aux cableAux cables wear out at the plug ends from repeated bending and unplugging.
- PossibleWrong source selected on the head unitThe system needs to be manually switched to the aux input; it won't switch automatically.
- PossibleWorn aux jack on the car or phoneThe jack itself can wear out from repeated use over years.
What to do
- Push the aux cable in firmly and make sure it's seated all the way, past any resistance.
- Try a different, known-good aux cable to rule out a worn cable as the cause.
- Confirm the audio source on the head unit is manually set to 'aux' or 'auxiliary input'.
- Wiggle the cable gently at the jack while playing audio to check for a loose connection that cuts in and out.
- Test the same phone and cable in another aux-equipped device to rule out a phone headphone jack issue.
- If a fresh cable in a confirmed-good jack still gives no sound, the car's aux jack itself may need repair.
Tools and parts
Aux cableSearch: “3.5mm aux cable replacement”
When to call a pro
If a new cable and correct source setting don't restore sound, a mechanic can test the aux jack and its wiring.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.