1999 mercury villager put in new blower motor and resistor. Every so often when change modes from defrost to lower for example or on start up it blows the front blower motor fuse. the blower motor is a Ford unit. Is there anything else on that circuit that could cause this. Going to try new blower motor relay.

Blower motor.

first check all your fuses then the blower motor relay and the blower motor itself, some times very rare cimate control goes bad but i dont think this is the case, hope this heps you.

The blower motor doesn't use a different fuse depending on the speed. The most common cause for your concern is bad blower motor resistors. The resistors lower the voltage to the blower motor so it doesn't turn at full speed when you have it set to fan speed 1. When the resistors blow out the only setting that works is full speed because it doesn't go through the resistor.

Check for 12v at the blower motor connector,

If no current then the switch is bad, or the relay is bad.

Obviously check your fuse as well.

Could also be your blower motor resistor if the fan only works on high speed on not the lower speeds.

All cars are designed with a blower fan motor that pushes air through the ventilation system. This air is processed by a series of vents to direct the air to various positions. Example: heater, air conditioner and defrost modes. Most blower motors are power by a basic electrical circuit that utilizes a multi resistor or a solid-state resistor to control different fan speed modes (low, medium low, medium and high). If the resistor malfunctions it may lose one or more of the lower fan speed settings.
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it means the blower motor is drawing too much current at start up. Are you saying it does it with old and new motor?
EATC or manual system?

go here for help

http://groups.yahoo.com/group/villagerquest/

is it blowing out defrost?
go here

http://groups.yahoo.com/group/villagerquest/

Was old blower not running?

remove the trim panel below the glove box and you will see the blower motor,just to the left of it you will see a 4 wire connector plugged into the case. This is the blower motor resistor,this is what you need to replace.

Hi..The Blower Motor Resistor is located under the glove compartment, pass side. You do not need to remove the glove box, or anything. Look under the dash on the pass side and you will see the resistor with the wires leading to it. (looks about the width of a Credit card) Simply undo the ( 2 ) 9 or 10mm screws from the resistor, slide/pull it down from the slot, un-clip the wire harness and replace with the new resistor. Screw it back up. Thats it. Takes about 4 minutes. The dealer wants $125.+ to do the job. The resistor is about $24.00.
Good Luck. If it keeps blowing, the blower motor is probably drawing too many amps. Then you have to switch that out.
Mike

if you locate the blower motor the rester is the wire that atachec to blower motor fallow wire till you find a circuit bord this is ur resistor