I have a '72 914 and took the gauges out to clean them. I marked all of the wires so that it would be easy to reconnect all the gauges when finished. I put it all back together but when I turn on the ignition, the horn honks and won't stop until I turn the ignition off. I do notice that one brown (ground?) wire is loose and not connected to anything. It's coming from the left turn signal indicator light. I've attached a couple photos. Is this the problem? If so, where should I attach it? I appreciate any help.

Did you remove the horn pad when you were working on it? Sounds like the ground terminal or wire from the horn pad is grounded out somewhere.

That's what caused my horn to do the same thing.... Pretty simple to fix. Not sure where that ground wire in your picture comes from/goes to but I did see a nice diagram of the instrument cluster wiring in a post a while back. I bookmarked it, but have since lost all my bookmarks (although they may be restored soon?). It looks like you are fairly new to 914World so if you haven't yet figured it out the best way to search the forum is to use google search and start the search with "914World" followed by whatever search terms you want to use. The internal search function doesn't work as well. Good luck!

This may help you out..and I agree on the horn ground wire under the horn pad.
An easy check and fix.

Click to view attachment

Thanks, everyone. Problem is fixed.