I have seen the owners manual or fuse map been incorrect many times and have resorted to checking fuses manually to see if they are bad, to answer your question, yes there could be more than 1 fuse, or even circuit breaker, the fuse you replaced, was it burnt ? That would tell you weather it was the bad one or not, also when there is a burnt fuse that means there is a problem that should be fixed, you say your heater-ac isn't working, I assume you mean the fan-blower doesn't work, if that's the case and you are blowing the heater fan fuse then your fan motor could be seized and need to be replaced, or there is a short in your wiring causing the fuse to blow, I would find the fuse that is bad, replace it and if it burn's out immediately you know you have a bigger problem, good luck.
what is it that does not work? Does your fan blower work when you turn it on or does it remain off?
It remains off
door Bryon Hodge