I KNOW there's someone out there that can answer this. The original horns on this vehicle work, but are not very loud. I bought a Steibel 132 db horn & hooked it to the battery to test and it is LOUD. So, OK.....Disconnected old horns, used original horn bracket (with slight modification) & hooked up ONE set of horn leads to new horn, leaving the other set alone. Horn works but 1/2 as loud. OK...Hooked BOTH original horn leads together, same result. Checked battery voltage @ 12.6vdc (engine off). Pulled airbag, checked voltage at BOTH horn switches: 12.6 vdc. NOW, the apparent problem: When I use jumpers to bypass either of the horn contactors (same as pushing the horn b utton), and read the voltage at the horn (with the horn disconnedted) I read 11.6 vdc. I have the horn schematic & see NOTHING on the print that would cause this voltage drop. There cannot be a problem in the electrical contact between the horn button harness & the "slip ring" because I'm reading 12.6 vdc everywhere along this circuit EXCEPT at the horn itself. Any ideas? Thank you. Ric Lang

 

Check for voltage drop due to bad ground.

 

the original and ancient wiring is causing excess voltage drop.

put a relay near the horn, use 12 gauge auto/marine grade wire from the battery+ to a fuse to the relay pin 30, relay pin 87 to the horn, other side of horn to ground.

wire the existing horn wires to relay pins 85 and 86. now your relay will get full juice.

 

Pierce & Tony.........Will recheck the grounds, but Pierce's suggestion seems more viable. The horn print doesn't show a relay, so I'm gonna put one in place. Stay tuned & thanks all. Ric Lang......PS What do you mean by "ancient? The car is only 28 years old.