Installed New Dual Sparton Horns (OER Item # MH108)

[sir_veza]

Hello, Long story short.
- Installed new dual Sparton Horns the other day. (Previously had a temporary single horn I completely forgot about). Just to get the car certified/safety years ago!
- Installed a new correct relay. (CHRYSLER Item # 3764532 and connected to the fuse box - existing factory wire thru the wire wall etc).
- Hooked up both horns to the correct vertical bracket behind the radiator
- Spliced the original factory wire so both horns have power
Issue is, when the motor is running both horns work fine. After the motor is turned off, both horns will honk once or twice together then only a clicking sound. Also with the motor off, if I disconnect a wire from one of the horns the other works fine etc. One at a time.
Not sure if I should run a new wire from the firewall back, or does anybody have any thoughts? Does anybody have the specific wiring diagram for the 1974 horn setup?
Thanks in advance,
Steve

 

[Challenger RTA]

When car is running power is also feed from alternator. Follow red battery feed wire on starter relay test for power and clean connections. firewall connections,fuse box, steering column connections.. check ground on column. could also be horn switch or relay. remove relay,jump horn relay with wire.Don't jump when horn blows. search wiring diagram you will find it there:

Power for Reverse Lights​

 

[sir_veza]

When car is running power is also feed from alternator. Follow red battery feed wire on starter relay test for power and clean connections. firewall connections,fuse box, steering column connections.. check ground on column. could also be horn switch or relay. remove relay,jump horn relay with wire.Don't jump when horn blows. search wiring diagram you will find it there:

Power for Reverse Lights​

Thanks

 

[72RoadRunnerGTX]

Sounds like the contact adjustment on that horn is off, try turning the screw a bit in.