You mentioned Relays, if there is a relay usually the current required to activate it is minor, so just about any switch should work.
Why you had a problem with the switch heating is weird you must have somehow had the locker current through the switch but anyway.
answer me some questions :
Does the Relay have numbers on the Connections, what are they ?
What are they hooked up too at this time, i.e. pin number X goes to XXX ?
Is there a schematic on the Relay ?
I am looking for the standard relay pin out, i.e. pins numbered:
85, 86, 87, and 30.
get back to us...
Do it right the first time !