i drive a 1998 oldsmobile intrigue gl

so when i have the settings set for winter: heater on full blast, and both front and rear defrost on. the rear defrost works fine. but the front defrost produces no defrosting ability and the heater fails to push any air out of the vents. my buddy took a look at it and says it's probably something with the heater fan. any suggestions or comments are helpful!

thanks for the help everybody!
****just some additional details i missed in the first post****

there is no air coming out of the vents. this points to the engine fan, I've checked the fuses and there are no missing or burnt out fuses. Im starting to think some wiring came loose when i hit a bump somewhere on the road. ill check the back of my accessories panel now...