Congrats on getting a Sonett!
I have two Sonett III's- a '73 and a '74, and BOTH of them came with really screwed up wiring! Man, could I tell you stories about what I found. The worst area tends to be the headlights and associated relays. They are a bit on the complex side and people cobble together all sorts of crazy things to bypass them, creating all sorts of havoc.
One of the best things to get is Jack Ashcraft's "Saab Electrics" book. In it, he redraws each wiring diagram for each year of the Sonett's in a way that you can actually SEE where the wires go. Then he has individual sections on each major circuit explaining how they work and how to troubleshoot them. It is most excellent and helpful and saved me HOURS of time.
So. The horn wiring. It is probably the most high-tech implementation imaginable! So sophisticated and space-age that it's beyond you to comprehend. Are you ready??
Okay, here's the deal- the horn button provides a ground to sound the horn. That's the copper-like connection you found on one side of the switch. The other side is the high-tech, space-age side. It's a black wire that is loosely wound a half dozen times around the steering column, feeds through the firewall and then makes it's way to the horn.
Yes. Wound around the steering column. So that if you turn the wheel to lock in one direction, the wire sort of unwinds under the dash. If you go the other way, it sort of winds some more around the steering column and tightens up. Until it breaks. And you get no horn. Which is what happened to yours.
The OTHER really cool failure mode is that it tightens up until the insulation breaks down, the wire shorts to the column, and then the horn SOUNDS. Every time you turn the wheel hard to the left or the right, depending on which way it's wound. My '74 has a Jack Lawrence built motor with a loud exhaust and it's bright yellow and draws quite a bit of attention. Picture this- driving slowly in the parking lot at work every day and every time you turn into the parking spot, the horn sounds until you can run the steering wheel back the other way. Slightly embarrassing...
So that's the story- find the break in the wire, check that grounding it at that point sounds the horns, and fix the break. Make sure you have a few loose loops around the column in that high-tech, space-age manner! No archaic rotating disk for the Sonetts!
eric in vermont
->Posting last edited on Sun, 5 Mar 2017 15:37:14.
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