Hi,

This is with a 1999 V70 SE RHD. When the car is left parked overnight - locked but alarm off, there is a loud rapid ticking or tapping noise coming from the OSF wing. It sounds like a solenoid or big relay repeatedly actuating. Naturally, it is running down the battery.

It doesn't develop immediately. It appears to take several hours to appear. It took roughly 36 hours (before being noticed, at least) the last time.

By pulling various fuses in a process of elimination, I found that pulling the central locking fuse stops the noise. However, it is proving very hard to pin-point the exact source of the noise. It appears to be right behind or under the headlamp but if I put my head close it appears to be coming from near the radiator. If I move my ear towards there it sounds as though it's coming from the control unit. Sometimes it appears to be coming from underneath around the wheel arch. In any case, whatever it is, it appears to be in close connection to the metalwork in order to amplify the sound.

After pulling the fuse the noise goes away making even harder to trace.

Has anyone else encounted anything like this or have ny idea what component might be making the noise? I found a thread that had a similar issue relating to the internal lighting, but that isn't the issue in this case. I also found (slightly) similar issues relating to an UEM unit, but I'm not sure if my 1999 model had one of these?

I'm currently pulling the fuse when I park but it is a royal pain - epecially since the car won't start without in place.

Any help or advice would be very greatly appreciated.

Thanks,
Keith