P2 in sprint electrical problems

I have just put a tuned elce start P2 motor in my 1965 sprint I put a beedspeed custom loom in it and chaged the back brake swith. when I start the scooter the horn is constantly on.
has any bodt got a wire diagram for this convesion and a list of other elctrical parts that i will need.
hal was going to give me a diagram but i lost his e male