1999 Camry Electrical issue..
 

I recently picked up a nice 99 Camry that had just had the TB done. Car ran great the first time that i drove it. The next time that I went to drive the car, it started up, but I noticed that the battery warning light was on. The most bizzare thing, is that the car was running, but had no electrical power at all. Nothing inside the car worked, and no exterior lights either. I had the use the shifter release button just to get the car in gear in order to move it into my driveway. I had a spare alt sitting around, so I swapped it out, but the light was still on. I had the alt that came off the car, as well as my spare tested, and both were good. I put one back on the car, and had the no power issue again. I checked the 100 amp alt fuse, and it was good. I pushed down on it, and presto the power in the car went on and off. I noticed that the fuse was an aftermarket replacement, so I swapped it out with an OEM one that I had from an old parts car. For a while everything seemed OK. Then when I was driving it the other day, the wipers went on and the ABS light also came on along with the battery light. After a few seconds everything was good again. The battery light went on and off a few time afterwards. I cleaned both battery terminals to see if that was the issue, but still getting the battery light. My main concern is that I noticed the the area of the 100 amp alt fuse seems to be getting pretty hot, and I could smell something burning. I disconnected the battery to be safe, and now it sits until I can figure this out. Anyone here have any ideas as to what I should be looking for?
Thanks in advance for your help.

The ABS fuses get power directly from the 100A fuse. No power to these fuses might cause the ABS light to come on.

Fuses and fuse boxes can get hot if too much current is flowing through it or there is a bad wiring at the box. Too much current should cause the fuse to blow. Bad wiring or fuse connection can increase the resistance of circuit which starts acting like a resistance type electrical heater.

The 100A fuse is between the alt and battery. With battery disconnected, might start by using an ohm meter to check for increased resistance between the black/green wire going to the alt connection plug and positive battery cable.

Suggest checking the wiring connection surfaces that attach to the fuse connectors, the connectors and wiring to them. It is possible the connectors, connection to the wire or wire has degraded. A connector can also be still attached to the wire, but the wire and or connector can become brittle or discolored from heat. Too much heat causes copper to degrade causing increased electrical resistance. Look for any discolored surfaces caused by heat.

It could be in swapping fuses, the wiring connections were OK for a time but they degraded again.

If you suspect a problem with the connector/wire interface, carefully slice the wiring insulation back to check the actual wire. The wire surfaces should appear bright and shinny like copper wire normally is. If discolored wiring cut it out until you find normal looking copper wiring. Be sure to also look between the wire strands for problems. Then reattach a new connector or if needed splice in more wiring.

Once you get to the point you think you can safely start the engine, check battery voltage engine running. It should be around 15 volts. If voltage is way up there such as 22 or even 30 volts there is an alt problem.