Blower motor only running on high...?
#1
Blower motor only running on high...?
Hello,
1985 6.9 Regular Cab long bed F250 4x4 with C6 trans, Cruise and Air.
Problem started with the second episode of smoke coming out of the ventilation system and filling the cab... First time I thought I had burned out the blower motor. Motor still worked.. Then I though I had burned out some wire under the dash.
This year the smoke came back and I finally found the problem..
Problem was that a mouse built a nest in my air conditioner right between the blower and the evaporator. What happened was the wire resistor for the blower motor that screws into the air conditioner area had set the mouse nest on fire.
Took the blower motor out and the resistor. Cleaned the cavity out and then reassembled the components. Ever since then the blower only goes on high and I'm freezing in the cab...
Any ideas what is wrong? Have I blown a fuse? Any idea which fuse? Or, have I burned out the resistor. I did take out the resistor and it looked fine...
1985 6.9 Regular Cab long bed F250 4x4 with C6 trans, Cruise and Air.
Problem started with the second episode of smoke coming out of the ventilation system and filling the cab... First time I thought I had burned out the blower motor. Motor still worked.. Then I though I had burned out some wire under the dash.
This year the smoke came back and I finally found the problem..
Problem was that a mouse built a nest in my air conditioner right between the blower and the evaporator. What happened was the wire resistor for the blower motor that screws into the air conditioner area had set the mouse nest on fire.
Took the blower motor out and the resistor. Cleaned the cavity out and then reassembled the components. Ever since then the blower only goes on high and I'm freezing in the cab...
Any ideas what is wrong? Have I blown a fuse? Any idea which fuse? Or, have I burned out the resistor. I did take out the resistor and it looked fine...
#4
Join Date: Mar 2009
Location: Maine (NorCal Native)
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It's on the heater box in the engine bay has 3 or 4 wires and look like this https://www.ford-trucks.com/forums/p...ictureid=37576.
Sorry for the poor cell image.
-Enjoy
fh : )_~
Sorry for the poor cell image.
-Enjoy
fh : )_~
#5
#6
87crewdually and Festus, Thanks for the pictures. My 85 is a little different, 3 separate wires to the resistor, no plug, but its located in the same place. I think its shot, when I took it out last time after the smoke it was embedded with burnt wood chips.... Off to NAPA this afternoon.
I believe if you think your saving electrons by putting the fan on low your not, just sending some of the energy through the resister and putting off heat instead of turning the fan faster.
I believe if you think your saving electrons by putting the fan on low your not, just sending some of the energy through the resister and putting off heat instead of turning the fan faster.
#7
redbug, there should be 4 wires, unless it's only a 2 speed switch in the cab. (Should be one for each speed, plus the... let's call it a return, as I don't think it is actually a ground.) A common issue on these is corrosion at that plug, I've had to dismember a couple of them and use spade terminals on each wire. Bit of a pain if you need to take it off later, but unless it's not working, something you rarely touch anyway.
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#11
I had an '84 Ranger in the past and dry leaves got in that resistor and caught the truck on fire! It was a roaring blaze before I got it put out. The resistor is actually in the ground wire for the blower motor. Running the ground wire directly to ground gives High speed on the blower. Running it through the different resistors gives you the slower blower speeds. As you can see the resistors are made of different diameter wire to vary the resistance and thus the blower speed. Those resistors get red hot and that's why it's mounted so that the resistors are inside the blower air chamber.
#12
Wow, too bad about your ranger... Maybe I should put remove blower motor yearly to check for leaves on my maintanence list...
Ordered new resistor. Old one does have four wires. One lone connector and a three plug connector. My local NAPA did not have it and could not order it. Advance auto had it for $30.
Ordered new resistor. Old one does have four wires. One lone connector and a three plug connector. My local NAPA did not have it and could not order it. Advance auto had it for $30.
#13
You're lucky that yours only smoked and didn't catch fire.
The louvers in the cowl (between the base of the windshield and the rear edge of the hood) on the 84 Ranger were slots about 3" or 4" long and 3/8" wide. I now have a 01 Ranger and it has a bunch of 1/8" holes punched in the cowl. Don't tell me Ford was not aware of the problem of leaves falling through the slots and getting into the blower chamber and then into the resistor.
The louvers in the cowl (between the base of the windshield and the rear edge of the hood) on the 84 Ranger were slots about 3" or 4" long and 3/8" wide. I now have a 01 Ranger and it has a bunch of 1/8" holes punched in the cowl. Don't tell me Ford was not aware of the problem of leaves falling through the slots and getting into the blower chamber and then into the resistor.
#14