No horns on my 99 D2, I have started the trouble shooting process and discovered the horn fuse was blown. Replace the horn fuse and it blew immediately upon insertion, truck off, no sound from the horns. The relay is open (I thought a short might be blowing the fuse) so I have no idea why the fuse could be blowing with an open relay. I’m going to double check the relay tomorrow but was looking for any insight as to what might be causing the problem.

I have a set of new in box Hellas that we’re going to go on another car but they might be destined for the D2.

 

I retested everything today from the ground up. I put a fresh fuse in and it didn’t blow, the relay clicks when I push the horn button. I pushed the button with the truck on and off just to be sure (I watched an AB video which said that the horn won’t go off with the truck off, not sure I believe that), still no blown fuse, but not horns either. My next step is to remove the grille and inspect voltage at the horns themselves and replace as needed. I can’t explain why the fuse blew immediately last time, I’m going to keep my eye on it but might just chalk it up to the magic of Lucas electrics in the meantime...

Right now I’m just happy my horn buttons work so I don’t have to replace those or mess around with the clock spring and all that good stuff.

 

It's easy to get to the horns behind the grill. I remember it's 3 screws on top and 1 on each of the bottom sides removed and you're in there.

 

Turns out the horns were shot, both of them. I got good voltage at the plugs when I pressed the horn buttons and suspect that the fuse was blowing due to an intermittent short in one (or both) of them. I installed a set of Hella Supertones I had around in place of the broken stock horns, not a bad install. I ended up just wiring them in to the stock horn wires and committing a minor sin by replacing the 10amp fuse with a 15 amp fuse as my computed current draw was 11 amps.

 

Looks good!