Heater blower issues
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Junior User
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Heater blower issues
Driving across country my blower would sometimes work......sometimes not. Got home and ordered a new vacuum selector with the 8 vacuum lines on the back which controls the blower on/off, vent, a/c, hi/lo heat and defrost.
Got that in yesterday and now the blower only turns on in the a/c position. The truck has the option for a/c but actually does not have it.
The blower speed is also screwed up. Instead of it working like it should:
-high
-medium high
-medium low
-low
it now goes:
-medium high
-high
-low
-low
The low setting and med-low have the same air flow output. Click it to med-high and that has more air out put than on the high position.
Fan switch i'm assuming. But running out of funds to keep playing the guessing game.
thanks for any input
-matt
Got that in yesterday and now the blower only turns on in the a/c position. The truck has the option for a/c but actually does not have it.
The blower speed is also screwed up. Instead of it working like it should:
-high
-medium high
-medium low
-low
it now goes:
-medium high
-high
-low
-low
The low setting and med-low have the same air flow output. Click it to med-high and that has more air out put than on the high position.
Fan switch i'm assuming. But running out of funds to keep playing the guessing game.
thanks for any input
-matt
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Junior User
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Thanks for the response. I looked most of the morning for it and can't find it. From my research it says there are 4 wires going to it and it should be along the orange wire for the blower somewhere. But looking at the resistor pic from autozone, it looks like there is only 3 wires.
Electrical is not my strong suit
Electrical is not my strong suit
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
Sounds like you have the Hi-Lo heating, that's basically factory A/C without the A/C part. It has the big evaporator housing under the hood, in-dash vents, etc.
The resistor is mounted in the plenum chamber that sits on top of the transmission tunnel, it's inside the cab. The resistor has two plastic rivets that hold it in place.
You can visually check the resistor to see if it's bad.
There are three wire coils, check to see if any of the coils are broken. If they are, the resistor is bad.
In the first picture, the resistor is behind the black wire, this picture was taken through the glove box with the liner removed.
It's hard to tell, but in the third picture, the middle coil is burned through so this resistor is bad.
The resistor is mounted in the plenum chamber that sits on top of the transmission tunnel, it's inside the cab. The resistor has two plastic rivets that hold it in place.
You can visually check the resistor to see if it's bad.
There are three wire coils, check to see if any of the coils are broken. If they are, the resistor is bad.
In the first picture, the resistor is behind the black wire, this picture was taken through the glove box with the liner removed.
It's hard to tell, but in the third picture, the middle coil is burned through so this resistor is bad.
MSEE
Joined: Apr 2004
Posts: 10,386
Likes: 35
From: Austin, TX
Are you sure nothing else got moved around? The selector switch only interrupts 12 volts to the circuit. The fan speed switch and resistor are downstream. They should not be related unless there's something else going on. For this to have shown up after the selector was changed, either something else had to have gotten moved, or it's coincidence. I'm betting on the former.
Lead Driver
Joined: Apr 2008
Posts: 6,938
Likes: 13
Sounds to me like you have soemthing loose on your vent selector, or internally the little contacts are not contacting. I had a similar issue on mine, finally i tore it apart one day and just kinda figured things out and got it working.
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just put my old vent/vacuum selector in and same issue. The fan only turns on in the a/c position.
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From: Stanley, VA
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From: Walpole MA
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i jumped the gun saying it was fixed! New blower motor relay came in today and i just put it on. Still have same issue! Jump those wires in the din with the relay off and everything works. Always something!
Any ideas??
Any ideas??
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
You're saying when you bypass the relay everything works okay, correct?
The blower is powered through that relay. It gets it's power from the bat side of the starter solenoid, but the relay is controled by the A/C mode switch which is a fused circuit.
First, I would check fuse F1 (30 amp) and see if its good. If it is, then I would unplug the relay and, with the A/C system turned on, check for 12 volts at the yellow w/ red trace wire.
Report back on what you find.
) hope it "sticks this time
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