nothinbuttodoit

I hope someone out there can help as I can trouble shoot with directions. I took electroncis and worked on older cars as a backyard mechancic. Ok here it goes. I have a 1993 Jeep cherokee Grand Loredo and this is my problem. My blower fan quit finally as it was intermittant for some time. I checked the blower fan by applying 12 volts straight to it and it spun up. When I check with a volt meter at the blower fan connector and disconnected where it goes into the wiring harness and I have the key on and fan selector on high I get 12 volts on the meter but it must be very low current to spin the fan as it does not spin once connected. I haven't checked the resistor pack yet as I have read that the high selector on the fan switch bypasses the resistor pack and comes straight from the level vent **** setting. So where I am stumped is, is there any other relays or fuses to check. Is it possible that ground is not right. I had always thought that motors on the black wire were always connected to ground and the red positive wire was selected for on and off to the device. I can always make a jumper harness with a switch and manually control the fan that way but I would much rather try to fix it the way it was built.
I am guessing I am going to have to tear down the dash to get to the a/c heater control panel any ideas or pictures as to how to do this so I don't break anything?