I have a 2001 Rover and the three Amigos are on, I'm working on another issue (I've got a pulley making noise and I'm trying to figure out which one). When I turned the rover off I could just barley hear something, as I search around I pin pointed the sound to the ABS box, it sounds like an electronic version of a horse galloping. So what is that about? Is that sound related to my three Amigos being on? By the way, the pulley just below and right of the AC unit move slightly in and out when the rover is running, would that mean that's the pulley making the noise?
Thanks to all for any input.

 

I don't know what that sound is but I've got 2 Discos sitting at my house and they both make that electronic chirping/galloping sound under the hood when the truck is off. It's normal I'm assuming.

 

Same here. I have the very faint chirp you can barely hear only with the hood open in a quiet garage. I hooked p a meter and it showed no draw on the battery, so no worries for me.

 

Same noise here too. Assumed normal and have never had a draw of rom the battery after sitting the truck for a week or so, so I am ok with it. That being said, like you I would be curious to know what the sound is and why it is running while the truck is off.
Always sounds to me like a computer gathering data?

 

Oh yeah, and had the 3 amigos, replaced with a new ABS unit and this noise is there after the repair, so I would assume it has nothing to do with the dash lights
01 SE, 116,000miles