Blower motor
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Joined: Feb 2006
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Blower motor
Is there any way to test the blower motor and switch? I don't think my blower motor is running at all speeds and need to test it. Is there a way to test the control switch at the harness that plugs into the motor itself? I would think the voltage would be different based on the switch setting.
Thanks!
Thanks!
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
I don't know anything about automatic transmissions.
My book shows your switch should have LO, Med 1, Med 2 and HI.
It also shows the same resister I have 4 wire connection on it.
Mine is located near the passenger side floor board in the heater box.
Yours should be close to there, wire colors on the connector are,
Black - ground
yellow/red - Med 1
orange/black - Hi
lt. green/white - Med 2
The Hi wire runs to the resistor, the blower motor and the switch.
Looking at the schematic, you have full power to the blower at all times when the air flow selector is moved from off.
So to run at lower speeds, the switch is adding resistance between the motor and the ground connection.
From what I see here, when the low, Med 1 and med 2 speeds are selected, the motor grounds through the ground connection on the resistor block.
When you select hi, the motor grounds through the dash speed switch.
My book shows your switch should have LO, Med 1, Med 2 and HI.
It also shows the same resister I have 4 wire connection on it.
Mine is located near the passenger side floor board in the heater box.
Yours should be close to there, wire colors on the connector are,
Black - ground
yellow/red - Med 1
orange/black - Hi
lt. green/white - Med 2
The Hi wire runs to the resistor, the blower motor and the switch.
Looking at the schematic, you have full power to the blower at all times when the air flow selector is moved from off.
So to run at lower speeds, the switch is adding resistance between the motor and the ground connection.
From what I see here, when the low, Med 1 and med 2 speeds are selected, the motor grounds through the ground connection on the resistor block.
When you select hi, the motor grounds through the dash speed switch.
Elder User
Joined: Sep 2007
Posts: 518
Likes: 0
From: Huntsville, TX
Good question! On my 85 I dont have anything but Hi and when I turn it on, it squeals like a pig for a little while, then it shuts up. I am thinking that the blower is going out. What yall think? Oh BTW, I dont have defrost either. Will only blow through vent. Weird.
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Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
Nothing but high is the resistor block.
If you don't think you have high, may be something in the air ducts.
Normally when high goes, you have no other speeds.
I guess the switch could cause you to loose high after thinking for a minute.
I think the first thing I would look at is the ground wire on the switch.
If you don't think you have high, may be something in the air ducts.
Normally when high goes, you have no other speeds.
I guess the switch could cause you to loose high after thinking for a minute.
I think the first thing I would look at is the ground wire on the switch.
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Post Fiend
Joined: Oct 2007
Posts: 10,501
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From: Faibanks Ak.
How are your brakes if your vacumn pump is bad your selector doesn't work but I'm thinking it is the other way around the defroster works.
Post Fiend
Joined: Nov 2003
Posts: 21,285
Likes: 16
From: Nutter Fort, WV
If the vacuum pump goes, the heater defaults to defrost.
Not getting the heater to switch to defrost sounds like something has fallen in a vent and blocked a door from moving.
Still if you only have high speed, there is something wrong with the resistor block.
Either it fried or the wires are off or the ground wire is loose.
The squeal is probably telling you you should line up a new blower motor, the bearings are about shot in the one you have.
I missed that last line of your post.
Not getting the heater to switch to defrost sounds like something has fallen in a vent and blocked a door from moving.
Still if you only have high speed, there is something wrong with the resistor block.
Either it fried or the wires are off or the ground wire is loose.
The squeal is probably telling you you should line up a new blower motor, the bearings are about shot in the one you have.
I missed that last line of your post.