1990 jeep cherokee sport heater blower?

Ok I bought this jeep about 2 weeks ago for like 700 bucks runs drives great. When i got it the heat was working fine, then it starting acting weird working sometimes and then quit for good the heat works still cause it defrosts some of the window from natural heat rising but the blower is not working at all. I dont know if it is common cause i had an 84 it had a toggle switch for the blower and i was wondering if i might half to do the same with this one cause i havent really done much research but i know its cold and snowy and it needs to be fixed pretty soon and i know quite a few things about jeeps from my first one.my current one only has 103k on it so any insight will be helpful thanks.

One of our jeeps has the same problem. 99% sure it's a vacuum leak, somewhere, but since the defrost is powerful enough that it heats the whole vehicle, we never bothered to track it down.

id agree with you but the heater blower motor is not functioning at all id be happy with just defrost if the blower was working abny other suggestions anyone?