I have a 1975 450 sl that i am working on.I can't get the ignition switch to engage the starter. I installed a new ignition switch and have verified power from the battery up to the block on the passenger wheel well. It would appear there is a break in the wire or fusable link from the ignition switch to this block. any ideas on where to look for a link between the two? I have 12 volts from the starter to the block on the wheel well and it starts just fine from there using a jumper wire. Do you know what color wire it is from the ignition switch to the block on the wheel well. I would be happy just to bypass and run a new wire. any help is greatly apprecated