[TerryJ]

The original horn relay on my 74 spider died. It does not appear that a repalcement is available. It is a Fiamm but I do not see any part numbers on it. There is a V. 12 molded on the bottom. Each prong is label with a number. 1 is associated with circuit 30/51, 3 is associated with circuit 85, and 4 is associated with 87. Does anyone know of an available part I can replace the old relay with? Terry

 

[rogerspeed]

Look at the wiring diagram on the electrical section. You need a generic three prong horm relay available at an auto parts store or here:Automobile, Truck & Motorcycle: Parts & Accessories

One circuit/prong goes to the horn button (negative/ground)
One circuit/prong is hot/positive (input) from the battery
One circuit/prong is hot/positive (output) to the horn