Try calling your local junk yard and locate a good used control unit.
Yes it will.
Look under the dash on the passenger side
You can try techauthority.com for the owners manual and fuse box diagram.
2004 ford expedition front blower not working
There is none - usually it is the module in the top of the heater / blower box (resistor module) that is the problem.
Blower motor resistor...around $25 on eBay
The problem might be with the switch itself. The contacts on the switch may be dirty, or the switch is worn out, causing the fan to stay on.
It could be the blower fan resistor or the relay
Behind the glove box.Remove the glove box and on top of the duct work for your heat is a little black box,that is your relay.Unplug it and replace it,plug the new one back in and your ready to go.
First check the fuses. If the fuses are okay I would suspect the switch and plug had a meltdown or the blower motor itself is shot. If it was the blower speed resistor that was shot you would still have high speed.
When the front blower for heat and a/c work fine and the rear does not on the 2001 GMC Yukon it could be a blown fuse. Automobile manufacturers rarely have both of these blowers running off the same fuse.
There are two probable causes. Assuming you are talking about a car fan, the screeching can come from a mis-alignment of the fan withing the cowl or shroud that conducts air to and from the fan. If you are talking about a home HVAC unit, the screeching probably comes from a slipping drive belt (or a tired hamster).