Heater blower resistor location

My girlfriend's 99 Cherokee needs the resistor for the blower motor replaced. The blower only works on high and I have been told this is the problem. Where EXACTLY is the resistor located and what does is look like so I know what I'm looking for.

Behind the glove box on the fan blower housing.

See also:

http://www.automotiveforums.com/vbulletin/showthread.php?t=490493&highlight=heater+resistor

Does this fix also work for heater emits hot air when driving at speed but blower motor does not engage?