2000 GS300 with AC issues
 

One day my cars ac was blowing cold to warm and back and forth. The next day it wouldn't blow period. I took it to hAVEit looked at and the guy told me after the mechanic hooked the blower motor to a power supply it worked but in order for him to do a complete diagnosis it would be $300. He also said its probably just a relay. My question is where is this relay located so I can change it.