can you do that without removing the grill?

 

You can, but it's easier with the grill removed.

 

Here’s a twist. None of my steering wheel controls (stereo or cruise control) work either.

 

sounds like a short in the column wiring.....

 

Bad spiral cassette is a possibility

 

So... I replaced the 10 amp fuse. It blew. Replaced with 15 amp. Horn now works. And the cruise cintros and radio controls work too. I noticed that the horn only sounds on the passenger side.

 

Driver side is dead, unplug it & I bet the fuse won't pop anymore.

 

Nice, Good find!

 

when I got my disco (nov), the horn didn't work...buttons in steering wheel were buggered. replaced the buttons, put a new fuse in and it sounded off again but
with a lame monotone....ie: single horn blowing. turns out the drivers side on mine is kaputsky.

anyone want to trade me a 190 deg new unused thermostat for one?