You might have a problem with your alternator since the combined load of what you listed isn't 90 amps. Do you have a clamp meter? Clamp meters are fairly inexpensive these days and super handy to have. I go around the car and check the amperage in every cable on the car to see what is going on. Often times you'll be surprised that one cable is carrying a lot of current while another one isn't. All it takes is a poor connection somewhere to mess things up.

Check your alternator output with the engine running and see how many amps it is producing. Check both battery cables as well as all the engine grounds.