Blower motor resistors are generally found nearby the blower motor.
usually on or near the top of the blower motor behind glove box area
The blower motor resistor is under the glove box. There's a plastic cover over it. You remove the cover and you'll see a connector that is plugged into the resistor. You can see pictures at www.timsjeepblog.com.
Can't give you a diagram but the blower speed resistor is under the hood, on the passenger side firewall not far from the blower motor in plain sight.
Blower motor control relay under dash behind blower motor is bad or has water in it from cabin filter port.
usually what causes that is the blower motor resistor. Get a volt meter and test it according to it's values, 90 percent of the time it's the RESISTOR.
Drop the glove box door and you will see it.
Bad blower motor? Blown blower motor fuse? Bad fan switch? Bad blower resistor pack?
I don't know how similar a '99 and a '95 are, but I've posted detailed directions (with pictures) for replacing a '95 blower motor resistor at www.timsjeepblog.com.
the resistor is located in the blower module which is located under the hood by the a/c evaprator case
Blower Motor Resistor Pack is defective.
More than likely the blower motor resistor pack is defective. The fix is to replace it.