I have a 76 cb400f with dyna ignition and 3 ohm dyna coils. There is way too much draw on the charging system and leaving me with a hybrid bike. ( plug it in every night) My question is how do I put in a resistor to make it 5 ohms? What size and where does the resistor hook in? Help please, I really don't want to buy new coils or put on the old ones.