Beeping when lights on

[Iceberg_UK]

Hi All,

I have recently purchased a W203 Estate of 2002 vintage. I changed the battery recently and since then there has been a beep coming from the near side rear storage compartment. No warnings are showing on the dashboard and it only beeps when the lights are on (side / headlights, brake light, indicators). I've checked for bulbs out and there are none although I believe there is a warning on the dash for this. I've checked that nothing is on the seat in case it interferes with sensors for seatbelts and again nothing although again I would expect a light on the dash.

I have a towbar fitted so am about to check the electrics for that.

Any advice would be gratefully received please?

Thanks in advance.

 

[RUBBER_UNDIES]

Hi All,

I have recently purchased a W203 Estate of 2002 vintage. I changed the battery recently and since then there has been a beep coming from the near side rear storage compartment. No warnings are showing on the dashboard and it only beeps when the lights are on (side / headlights, brake light, indicators). I've checked for bulbs out and there are none although I believe there is a warning on the dash for this. I've checked that nothing is on the seat in case it interferes with sensors for seatbelts and again nothing although again I would expect a light on the dash.

I have a towbar fitted so am about to check the electrics for that.

Any advice would be gratefully received please?

Thanks in advance.

It sounds like to me that it is the buzzer/bypass relay for your tow bar.

 

[Jason-uk2018]

It sounds like to me that it is the buzzer/bypass relay for your tow bar.

Thank you, that's exactly what it was. I took the fuse out and will sort the problem when I have time. Possibly a short in the plug, or other wiring issue?

 

[RUBBER_UNDIES]

Thank you, that's exactly what it was. I took the fuse out and will sort the problem when I have time. Possibly a short in the plug, or other wiring issue?

If it's aftermarket. Just change it. They get moisture In them and shorts the relays out.