all i remember from a previous post is that it has something to do with
replacing the resistor

There is a resistor pack in the duct, usually behind the glove box. You
need to replace them with an oem piece (not resistors from an
electronics store).

It's a printed circuit board mounted behind the glove box area in something
that looks a bit like a letter box in the bulkhead with one (or is it two?)
screws holding it in place.  Undo the screw and pull.  If you look at the
board carefully you'll see a few soldered joints that are bridging tracks.
There are no components, the tracks are the actual resistors, and normally
it's the solder joints that go open circuit, so all you have to do is
resolder them.  Another regular problem is the pollen filter if you have
one, it gets really clogged up and the ventilation power drops off.  You
have to actually remove the glove box to change that.