Living in the Past
SILVER Star
Installed Apple Airtag to be able to find FJ40 if it wanders. Cheap option for GPS tracking and installed a kill switch. If somebody really wants the FJ40, I'm sure they will find a way. Hopefully the kill switch/horn will irritate them or at least slow them down. Here is the wiring diagram that I found on the internet that I used. I installed the horn inside the cab under the dash. I ignored the neutral safety switch in the diagram, it was not an option on my 1973 FJ40.
View attachment 2680423
What you need is a second relay the is double pole single throw. Need to ground the one side of the coil then the wire going to the horn go to the other side of the coil. Now get a 12 volt power source to one side of each pole. Other side of the poles one to the horn and the other back to the positive side of the coil. That way once the relay is triggered the coil still has power and continues to keep the horn going. Just need a second hidden switch that breaks the new power to shut it off. If the ignition switch isn't you can switch the power back on. This way instead split second of the horn until the ignition switch is stopped the horn keeps going. Label the second relay HOLDING RELAY. Personally like breaking the wire going to coil verses the starter. Or just pull the rotor out of the distributor. Someone is not as likely to be looking to turn a kill switch if the engine turning over. Also on a 73 unless it has an automatic transmission there is no neutral switch.
