or should I keep the 6V relay and install a voltage resistor in front of the relay?
Yes...in front, meaning before the relay. Voltage reducer at Classic Trucks of America.
Some folks on here just run the horns on 12V with short toots.
the original 41 cars did not have a horn relay for a single horn set up.
The relays being sold for 40's and up old vehicles are not voltage specific. It's all about the voltage the horn wants. You could put the reducer on the relay input or output. (front or back), With those relays.
Last edited by bartamos; 10/14/2022 10:01 PM.