blower motor

just replaced the heater core in my 88 and now the blower is dead ive checked and double checked my connectors and they all seem to be pluged up i am going to assume its either the motor or the switch in the controls how do i know which one

Check the fuse. you "might" have blown it the positive wire touched the dashboard metal when reinstalling it

also check the resistor that the plug goes into. It'd be suprising if they all went at once, but i've seen it happen before. Should be two screws holding it into the blower motor where the plug goes in.