E30 Zone

first of all its a 1989 325i Tourer
The car had been standing for 5 years and now have decided to put it back on the road.
I Checked the oil, flushed the water, and got rid of any airlocks and started the car with no problems.
Took it for a little drive and everything was good. So, I parked the car up and locked it (for some reason the car wouldn't lock from the drivers door but locked fine from the passenger side.

A few hours later, I walked past the car and noticed a constant beeping coming from the alert speaker in the footwell area
its not three beeps then stop, its just constant, even when the car is turned off and key out the ignition, when the car is locked, unlocked, just all the time!
I started the car with no issues but the continuous beep was still there, then it faded away and came back a second later. I checked the settings on the obc, no speed at limit settings active.
its not the memo or temp.
for now i've had to disconnect the speaker, but i still want to fix the problem.

Can anyone help?

I have a 325i Sport and I also have a constant beep, although I don't know where it is coming from. It however only happens sometimes, either when I drive or even when the car is not on. It also happens that I cannot start the car at all, which is more annoying.

I unplug the battery for as little as 1 sec, re-plug it, and then the car starts again, but the beep is still there. I need to leave it like this or unplug the battery for a long time for the beep to disappear.

I have not found any sustainable solution so far, so unfortunately I cannot be of any help.

The gong sound is produced by an amplifier producing a constant tone through a small speaker. The amplifier has an electronic volume control, which is normally held fully off. The gong sound is produced by momentarily turning up the volume, and then reducing it back to zero.
In your cases, the volume control is slightly turned up all of the time.
The tone generator, electronic volume control, amplifier and speaker are all part of the chime module, and the volume control wire between the OBC and the chime is (I think) a brown/blue wire. Try disconnecting just this wire from the chime, and see if the noise stops.
I know that I've come across this problem on one occasion, but I can't remember what the solution was, and I don't appear to have made any notes, like I normally do.

vivienhallebard: The OBC also contains the 'code' immobiliser, which on all E30s can be defeated simply by disconnecting the battery for a second, so I wonder if both your symptoms are caused by a failing OBC.