you need to be more pasific buddy
Unhook your horn and hot wire it from the battery to see if it work. If only one wire is going to your horn that should be your hot wire so gound the negitive wire from the battery to your body.
Use wire to briefly connect the horn directly to a known good battery. If it sounds investigate horn switch, wiring and horn relay if present.
To replace the ignition switch on a 1982 Mercedes 300SD, disconnect the battery and remove the horn pad. Locate the wire behind the horn and remove.
It it either a blown fuse, defective horn, bad ground, or defective horn switch. Check the fuse, if it is blown, replace, if it is good, run a wire to the horn directly from the battery. If the horn blows, suspect a bad horn switch.
if its not the alarm malfunctioning, there is a short circuit somewhere between the switch/battery/relay and the horn its self - youll have to find the short and insulate the wire or replace the switch.
You can test the horn unit by connecting one end of a wire to it and momentarily touching the other end to the battery positive post if the horn unit is grounded.
I used to have a replica on my pickup. All you have to do is have a hot wire that is connected to a aluxary switch to the horn. The horn must have a good mounting for a ground or a ground wire.
Connect the positive lead to the battery or a spare positive terminal at the fuse panel, run it to the switch with an in-line fuse, run from there to the positive terminal on the horn. Mount the horn and connect the ground wire to ground on the chassis.
Checked the fuses. Tested the horn, direct connection to the battery. Check horn relay. Here is the basic. Between the horn switch and the horn relay is the Clockspring Assembly in the steering wheel. If you ground the red/green wire at the base of the steering column and the horn works, you have either a bad horn switch or Clockspring Assembly.
hook a wire up to the (+) side of the battery and put it to the horn if the horn blows it a good horn if not replace the horn
Answer 1Yes, but... you will need wire heavy enough to carry the current [measured in Amperes or Amps] that the horn uses, and also need to install a control switch in the circuit or the horn will sound continuously. The hookup is simple: one horn wire to the Positive [+] terminal and the other horn wire to the Negative [--] terminal.It would also be a very good safety practice to install a properly sized fuse in circuit to protect the conductor wires.
You may have the wires for your horn crossed with the battery wire. This would cause the horn to go off any time the battery is connected.