PW/WC/M37 horns have voltage applied to one horn wire. The other horn wire goes thru the horn button on the steering wheel to ground to operate the horn. By using a relay, we can use a much smaller motor brush to operate the horn. All relays will be marked with the terminals and their assignments. You need to use the normally open contacts for horn operation.
On the Potter Brumfield relay Pin # 30 goes to the horn ground wire. Pin # 87 goes to truck ground. Pin # 85 goes to the copper ring you mounted on the steering column ( described eariler). Pin #86 goes to 12 volts thru a 1 amp fuse. The wire from the horn button attaches to the motor brush which rides on the copper ring.
When you push the horn button, the relay is operated, closing the normally open contacts and operating the horn. The relay used for 12 volts is a Potter & Brumfield VF4-45F11. For 6 volts, you will have to buy a relay rated for 6 volts with normally open contacts. The hookup is the same for 6 or 12 volts. You can also buy small relays at Electronics Supply Stores. You must be sure that the relay contacts will handle the current draw of the horn. The 12 volt horns on my PW and Carryall draw 10 amps when operating.
On the Potter Brumfield relay Pin # 30 goes to the horn ground wire. Pin # 87 goes to truck ground. Pin # 85 goes to the copper ring you mounted on the steering column ( described eariler). Pin #86 goes to 12 volts thru a 1 amp fuse. The wire from the horn button attaches to the motor brush which rides on the copper ring.
When you push the horn button, the relay is operated, closing the normally open contacts and operating the horn. The relay used for 12 volts is a Potter & Brumfield VF4-45F11. For 6 volts, you will have to buy a relay rated for 6 volts with normally open contacts. The hookup is the same for 6 or 12 volts. You can also buy small relays at Electronics Supply Stores. You must be sure that the relay contacts will handle the current draw of the horn. The 12 volt horns on my PW and Carryall draw 10 amps when operating.
Other Sizes: Medium