Ok

you have 3 wires, one is the big ass red from the battery, another red which is actually made of two thinner wires, theyre the main charging lead, these both get put on the same terminal, they should only fit on one, and are secured with a 13mm nut, and the solenoid energiser wire will be black & Red. or black & blue or black & yellow (i forget which), now this wire can have a few different connections, some are ring terminals, some are female spades, what is on your loom and what spare connectors are on the starter? A pic of the motor would be handy.