Hiya, sorry if this has already been posted, but my friend has a problem with the reverse parking sensors on his 325. The back far left works fine but the other 3 dont work at all. When he puts it in reverse ( this is when the ignition is not running but the lights are on) it makes a single beep noise, but he can hear a ticking noise coming from all of the sensors at the back. He has read that its possible for them to get damp would this be the case or something else. He also has a light on the dash which means one of his rear lights is out, we've checked every light fog, brake, side lights and they are all working fine so why would the light on the dash still be lit? any ideas guys. many thanks.