blower motor resistor
01-19-2003, 10:52 PM
#1
Le Mans Master
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St. Jude Donor '03, '04 & '05
blower motor resistor
Where is the resistor located, and what the heck does it do???? (on a '66) can it make the heater fuse blow??? :confused: Thanks!
01-20-2003, 12:08 AM
#2
Le Mans Master
Re: blower motor resistor (RichF)
Well, I guess it could, but I have never seen much problem with them. On a non AC car, it is located behind the heater box on the passenger side of the car.
01-20-2003, 12:12 AM
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Re: blower motor resistor (RichF)
It's located in the heater housing with the spades for the connector poking through the outside. I adds series resistance, which cuts voltage to the motor and gives you the three speeds. Low and medium speed cuts voltage by adding series resistance to the circuit. High speed is straight through - no series resistance - full voltage to the blower motor.
If you are blowing a fuse it is probably a "short to ground" - a "short circuit". I don't think the resistor can short to ground since it's mounted in the fiberglass housing. Same with the blower switch. A shunt to ground is most likely in the wiring or the motor itself.
DISCONNECT THE BATTERY! Probe the motor terminal to ground with a multimeter. It should have a little resistance- an ohm or two. Then probe the motor power lead. Try it with the fan switch is all positions and jiggle the wires around. It should read infinite no matter what. If it shows finite resistance there is a short.
Mounting the resistor in the heater case keeps it cooled with air flow.
Duke
If you are blowing a fuse it is probably a "short to ground" - a "short circuit". I don't think the resistor can short to ground since it's mounted in the fiberglass housing. Same with the blower switch. A shunt to ground is most likely in the wiring or the motor itself.
DISCONNECT THE BATTERY! Probe the motor terminal to ground with a multimeter. It should have a little resistance- an ohm or two. Then probe the motor power lead. Try it with the fan switch is all positions and jiggle the wires around. It should read infinite no matter what. If it shows finite resistance there is a short.
Mounting the resistor in the heater case keeps it cooled with air flow.
Duke
01-20-2003, 01:03 PM
#4
Le Mans Master
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Re: blower motor resistor (SWCDuke)
Duke:
Thanks.. Well, that solves one of my problems,.. I had the heater core replaced - when I left the car, all 3 speeds worked on the blower... when I got the car back only high speed worked, - Yesterday, I went looking for the resistor... I found the spades, but guess what??? no wires connected to it... I wonder where in the heck they are now????? ( not dangling close by :( I figure that wouldn't solve my short, though....
Thanks.. Well, that solves one of my problems,.. I had the heater core replaced - when I left the car, all 3 speeds worked on the blower... when I got the car back only high speed worked, - Yesterday, I went looking for the resistor... I found the spades, but guess what??? no wires connected to it... I wonder where in the heck they are now????? ( not dangling close by :( I figure that wouldn't solve my short, though....
