72 dodge Motor home 360 I keep blowing 20 amp fuses ,between amp meter and battery + which has to extra hot leads,one lead to hot side of double terminal relay for the coach aux.. The other lead runs solid through fire wall to amp + with 10 gauge glass type fuse inline. Hot line (pk) from Ign.to ballast resistor ,is piggied with fuse, to Ign. terminal on relay's small post and (Grn.) on the other to ground,then two leads on other large post to ACDC & Aux Batt..As soon as i let go of key after Ign.,fuse blows volital but eng purrs.Cranking eng, with Dist, cap off no blow.New Alt./ V Reg / Bal Resit./ start Relay..Thank you....Mick

Optional Information:
Pre-1981 Dodge B 300 360

Already Tried:
checked main lead from Alt./any loose or bare wires.