97 Pathfinder Heater Blower

I've got a 97 Pathfinder and just had the alternator go on me. Had that replaced along with a couple of fuses it blew, and since then my heater blower has been acting erraticly. ie...it'll blow fine for a while, then start fading in and out and only blowing at maybe 50% for a few seconds. Then jump back up to normal power. Any idea's? Thanks much...

Had to replace my blower in my '98 Pathfinder for the same erratic behavior. Happened after my alternator went out on me, too.