I only have a wimpy high pitch horn so I took a look inside the wheel well to figure it out. I have a Hella disk horn which doesn't appear to be getting any current. I also have two trumpets. The blower motor works fine and blows air to both trumpets. But the short one is all that actually makes a sound. The long one doesn't. I can try to find a replacement for one or both trumpets.

The lack of current to the disk horn is what's concerning me. I put a DMM on the contacts and honked it. It reads 0 volts. I looked at the wiring diagram and both the disk and trumpet horns come from the same relay and fuse, both good. So it appears that there is a wiring fault to the disk horn. Does this sound right? It looks like a royal PITA to pull apart the wiring trunk and try to find this fault. Should I try to do this or reroute power from the trumpet blower?
Thanks.
Chris

 

Chris,

I don't know what set-up you have there - but it doesn't sound very standard!! In a "standard" 964, the two trumpets are both electrically operated - not air, and the disc horn you mention is specifically for the alarm - not for the pedestrian scarer.

It's quite common for the trumpets to pack up - the diaphram suffers from age. I had to replace both of mine. They are not terribly expensive form your OPC.

REgards

Dave

 

Ah, that's good news. My alarm works, but I forgot that it was different than the horn because I've only set if off once. So that just means that I need to fix the one trumpet or replace the whole set-up with something else. Thanks!

 

I had exactly the same problem not so long back. I took them apart to see how they worked because that's what I’m like. Very simple mechanism inside once you understand it.
First thing to do before you throw it away / take them apart is -
Release the horn that doesn't work so it is still connected to the wires but hangs over the front wheel. It's only one nut / bolt.
CW Quarter / half turn the hexagon fine adjusting screw on the back of the horn and keep pressing it to see if you get any life. don't go made turning the screw it's a fine adjustment only. If that doesn't work, turn the other way and keep pressing the horn to check. If that doesn't work, it's time to get the screwdriver out.

SORRY - I don't have any pictures but I can explain everything if you want. Just let me know.

Chris W.

 

I had the same problem as well. However I also had a cold solder joint on one of the coils. DVM showed 0 ohms. Resoldered all the joints, put back together and adjusted pitch screw. Now it works.