causes of complete electrical failure in a '99 Toyota Camry?
 

If it is not the battery or alternator what are the next most likely causes of complete electrical failure in a '99 Toyota Camry?

What is the falure? Battery goes dead (parasitic load)? or charged battery but no conductivity to the system (damaged wire / blown fuse)?

If the battery is charged and you do not have any power to the electrical system you should start by checking the battery connections. I would start with checking the Battery cable connections to the battery, then the ground to the motor block, then motor block to the car body, ect till you find the break in the connection.

If it is a parasitic load you should charge the battery and set up an amp meter to measure the amp draw. Then you can start pulling fuses to find the system that is causing the problem. Troubleshoot that system as necessary.

Good luck!

Fusible Links
 

Be sure to check the positive battery cable is connected to the alternator.
After the cables check out, a fusible link should be the culprit.
They tend to be hidden in with the wiring harness bundles. They basically are small inline fuses. Look up the electrical diagram and look for one near your alternator or starter and then trace the wires out using their color codes and sure enough you should run into the fusible link u r looking for.

^^^^ What he said... :)