Adjustment
OK, so the horn is basically complete again, ready for adjustment.
DO NOT mess with the nut labeled "NO". That's the fixed end of the breaker bar.
Put an ohm meter across the 2 terminal screws.
- If you have NO continuity, turn the adjust screw IN (clockwise), just until you DO make continuity.
- If you already DO have continuity, turn the adjust screw OUT (counter-clockwise) until you just lose continuity, then back IN until you just make continuity again.
- NOTE the position of the screw head for later reference. This is endpoint #1
Now connect the horn to a battery, or 6v power supply capable of at least 5-6 amps, that won't blow fuses when it's short circuited. One with an ammeter on it is ideal, but not necessary.
If you can wire in a push-button to simulate the horn button, that's good, but not necessary. Just leave one wire disconnected from battery/power supply, and touch it to power to test.
With initial continuity already established from the procedure above, when you connect the horn to power, it will sound off. It will sound like crap at this point, very weak and anemic. That's normal.
Find the adjust screw endpoints. The range of adjustment is fairly narrow, only about 3/4 turn from "no continuity" (the points never close), to "all continuity" (the points never open):
- Turn the adjust screw inwards until the horn stops working (all you'll get is a "klunk" when you press the horn button).
- NOTE the new position of the screw head. This is endpoint #2.
- Set the adjust screw about mid-way between the #1 & # 2 endpoints.
If you have an ammeter to monitor current, you should see about 3-3.5 amps at the #1 endpoint (where continuity was just made), and 4-5 amps at the #2 endpoint, right before the horn stopped working as the adjust screw was turned in.
At this point, the horn still sounds like crap, but now we'll make it sing! With the points adjusted as above:
- Turn the center striker slug inwards slowly, 1/8 to 1/4 turn at a time. You'll reach a point where the striker plate on the diaphragm starts hitting the striker slug (NOW it will start to sound like a real Jeep horn! and LOUD!)
- From that point, turn the striker slug in just a tad more, about 1/16 - 1/8 turn, no more!
- Tighten the striker lock nut.
Install in Jeep. Enjoy!