Horn Relay Options

[Tobra]

Did a search, but the answers are not really jibing with the manual. I can hear the thing clicking under the dash, but no beep beep. Is the horn relay one of the black round ones on the Fuse Block? What else is on this relay? I hate to drop the cash for a round relay just to fix the horn, can the round relays be repaired?

[Dave_Darling]

Check the colors of the wires going to each of the round relays that live on top of the fuse panel. One of them will be the horn relay (unless your car is one of the very early ones without a relay--or did I misinterpret the wiring diagram?). You can swap any of those round relays for any other; they are identical on the 914. Try swapping with one of the headlight motor relays--if the headlight doesn't raise and lower any more, you know the relay is bad.

You can probably fix some bad relays--you can pull the plastic off and see the guts when they get old enough and the glue holding them together gets worn. (Or is it a friction fit?) It's just an electromagnet and a couple of contacts that are spring-loaded. Let me find my pics...

Relay exterior:
(IMG:http://members.rennlist.com/damp_dave/Fig_4.JPG)


Relay bottom, showing connections:
(IMG:http://members.rennlist.com/damp_dave/Fig_5.JPG)


Relay guts, from the side:
(IMG:http://members.rennlist.com/damp_dave/Fig_6.JPG)


Relay wiring diagram:
(IMG:http://members.rennlist.com/damp_dave/Fig_7.JPG)


Relay guts, better view:
(IMG:http://members.rennlist.com/damp_dave/Fig_8.JPG)


Relay guts, from spring end:
(IMG:http://members.rennlist.com/damp_dave/Fig_9.JPG)


If you can hear the relay click, it almost certainly is not bad. I'd check the wiring to pin #30 of the relay, and the wiring from #87 on the relay to the horn. And the ground for the horn, of course.

--DD