Toyota Repair: 1990 Toyota Supra, toyota supra, auto parts store

Question
My son has a 1990 Toyota Supra. 101,000 miles, manual transmission. He hooked up the battery wrong (neg to pos, pos to neg).  Now the car is completely dead.  No domelights, nothing.  I have checked all of the main fuses and all are okay. The battery has been tested by an auto parts store and it is fine. What are the next couple of steps that I could take to find the problem?

Answer
Under the hood, check the 30A AM2 fuse, remove the clear plastic cover and check it with a test light, if it's open check the white wire coming from the positive battery terminal, this is a fusible wire which will burn out if there is excessive current draw, this wire may be open between the battery and the AM2 fuse which supplies voltage to most of the rest of the electrical system,  fusible wire is available at any autoparts store.