I just noticed this morning that I hear a slight "ticking" sound that seems to emanate from the ABS block when car is off. Anyone else got this? It must drain the battery right?

 

I have always had a faint electronic buzz, buzz, buzz that comes from the fuse/relay box behind the battery. Never killed the battery though.

Don't think I've heard anything from the ABS area.

 

Yes Matt, it's quite normal. Mine ticks whether the ignition is on or off. The ticking is like a reasonably quiet clock and a barely perceptible tick unless it's very quiet around you. Best way is to listen to the ABS modulator with a mechanics stethoscope, but again, it's quite normal. No perceptible battery drain.

 

Both of my DII's ('01 & '04) behaved this way. Not sure why...

the only explanation I found is that the SLABS unit stays under power 1.5 hours after the ignition was off for the SLS part of the system... so some inductive current or false signals are getting to the modulator which makes the internal solenoids to click randomly...water ingress is quite common at the SLABS ECU which might favour this behaviour

I Never had a battery drain concern or issue.

 

Perfectly normal. My DII makes quiet ticking noises from both the driver and passenger sides. And whatever it is it's not enough to cause any meaningful battery drain.