Blower Motor Control

UNder the dash and behind the glove box the blower motor has a connection that was corroded. My question is what is that the plug is plugged into? Is in the reostat for the blower or something else? The reason i ask is that the blower stays on high regardless of where the speed dial is. I pulled the unit out of the bottom of the heater and it is extrememly corroded.

Anyone have ideas?

Many blower motors have resistors to change speed...High - no resistance, 3/4 - little resitance, 1/2 - moderate resistance, 1/4 maximum resistance. I pulled the blower motor on my 93 1.9L and don't remember seeing a resistor pack...could be internal and motor disassembly is required. Or, it may be that the resistance is provided in the switch.

Alright, the resistor theory is dead on. The resistor pack is not in the blower motor but rather in the firewall at the front of the passenger footwell. That is where it should be as I have seen it in many Fords in that same place. Get down low in the footwell and you should see a harness connected to a rectangular plate with a part # on it. Disconnect the harness and pry that plate out. On the back side is the resistor pack. The reason this happens is because cabin air filters will become old and clogged not letting much air through. Air blows over the resistor pack before it passes through the blower to keep the resistors cool. With restriction the air does not come through easily to cool the resistors and the blower works harder putting more strain on it and the resistors. Your dealer should have an updated part # and they cost about $15.

Attikus1 (http://www.automotiveforums.com/vbulletin/member.php?u=433665) vbmenu_register("postmenu_3777446", true); Thanks for your help, I thought that what it was, however no manual (that i could find) explained what it was. I wil replace and let everyone know the results. Thanks Again