So far the forum has been spot on with repair needs to my discovery II and saved me tons of money.. Here is my latest semi-crisis.. I'm cleaning my truck and wiping down the dash when suddenly my radio is on.. I look and well there are no keys in the truck. I can actually see them hanging up where we put them. sooooo. I've turned the radio off, but my concern that it will still be drawing power and drain my battery... Any thoughts suggestions? Also my horn button popped out awhile back.. just need to find the fuse to unplug the horn then I can fix it i'm sure.

 

all discovery stereo do that I don't know why but the operate without the ignition on.

 

Horn fuse is number 16 under the dash. Edit make that under hood, my bad.

RAVE manuals are your friend, free download links below.

 

Mine doesn't.

 

is it a stock radio? shut your truck off and you should be able to turn the stereo back on by hitting the button.

you have 04 I believe it is a different stereo, but not sure.

 

Turns out you are right. It does come on without the key in the ignition. Never knew that. Thought I had tried that before.

 

Evidentially, it's a common issue. I've seen the replacements for sale all over the place. Like below:
discovery horn button | eBay

 

It will come on, with out the key if you just push the volumm button and then stay on for 20 minutes.

 

Fuse 16 in engine bay on mine.

Yep, I hate those buttons. My right one doesn't have any broken tabs and it still pops out if I hit it wrong.

 

It's funny, but I don't think I've EVER hit the horn on this truck. I'll have to try it. You'll know if you pass me on the road today, I'll be the one honking at everyone!