I have a wire going from the alternator to another spot on the motor...would that be the starter?
If it's orange, and about 3/16", then yes, it goes to the battery lug on the starter. (as slong as it's stock Mercury)
What are they wires that usually come off of the alternator and where do they go?
For Mercury, (and most other's) there is
1) Orange wire to battery. (usually connect's to the battery lug on the starter)
2) Red wire from battery source. (ususally the engine circuit breaker)
3) Purple wire from a switched (ignition) battery source. (usually tied with power for the audible warning system)
4) Black wire to ground. (usually the engine block.
This is for most Mercury stuff prior to the 496 stuff.... I am not to familiar with the modern electronics. ie: SmartCraft.....
Save the greif and convert to a "one wire" alternator.