Toyota Repair: 1995 4 Runner electricel problems, electrical issues, best guess

Question
I have been having electrical issues with my 4Runner for a bout a month now. The battery gage was going down and the lights would dim when I applied the brakes. I took it into the shop and they told me the battery had poor health, so they replaced it.  The problems continued and I brought it back to the shop.  they did some diagnostic testing and eventually replaced the alternator.  Now, when i drive it, if I put the blinker on to the left it will shut down all power and kill the truck.  This also happens when i put on the brakes.  But not all the time.  I think it should be a short in the wiring, but I am not blowing any fuses.  What else could this problem be?

Answer
You said this started about a month ago, right before that did anything happen, was it in an accident, were any other repairs done before this started, since it seems that the problem with the engine dying when using the blinker and the brake lights may have somehow be caused when the alternator was replaced, that's my best guess, and yes if there was a direct short to ground some fuses should blow.
I can't see any connection between the brake/turn signal wiring and the engine wiring.