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Unread 10-29-2008, 07:22 AM   #1
K_2
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Heater blower constantly running

My heater blower is constantly running but when I move the control up and down for fan speed it does nothing? Don't know if this is related but I found two wires with terminal ends in the engine bay along the left side top of the motor not connected to anything. They look as though they should be going to the carb but can't find anywhere they should be plugged into.

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Unread 10-29-2008, 07:40 AM   #2
Que89YJ
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Blower

Nope, the blower switch is probably not the issue. Look in the FAQ and check the resistor block.
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Unread 10-29-2008, 07:41 AM   #3
K_2
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Quote:
Originally Posted by Que89YJ View Post
Nope, the blower switch is probably not the issue. Look in the FAQ and check the resistor block.
Where is the resistor block located?
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Unread 10-29-2008, 07:45 AM   #4
blue1989yj
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I beleive it is right below the vent under the glove box.
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Unread 10-29-2008, 07:47 AM   #5
K_2
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Is it a small thin plastic or metal piece? What is it's function?
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Unread 10-29-2008, 08:00 AM   #6
Que89YJ
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Heater block

Its a set of heavy duty resistors mounted on a "block" that sorce the current from the 12VDC supply of the car to change the blower speed. Its a common fail part. Due a quick search and you should have no problem finding the info to replace it.
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Unread 10-29-2008, 08:12 AM   #7
EABiker
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Actually, mine runs all the time too unless I shove something under the selector lever in the OFF or VENT positions. Mine is just a worn out switch, (better always on than always off!). The speed selector still works, which is a good way to diagnose the resistor.
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Unread 10-29-2008, 08:51 AM   #8
Que89YJ
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Switch

You have a good point. Is it on even with the switch in the off postion? His post says that speed doesn't vary with the speed switch, but a short across the switch will do the same thing. If the off switch is functional it still makes sense that its the Resistor block. If the control switches do nothing, then it is probably the switch.
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Unread 10-29-2008, 01:46 PM   #9
K_2
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I can't seem to find them. It's prob right in front of my face too! Any more help....
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Unread 10-29-2008, 02:12 PM   #10
gary1
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If the resistor is bad, it will always run on high, but may be burnt out for some or all of the lower speed settings. In that case it wouldn't run at all on some or all of the lower settings. I would guess that your switch is bad. Also, there is nothing in the engine compartment that would have any effect on this.
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Unread 10-29-2008, 02:31 PM   #11
K_2
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Quote:
Originally Posted by gary1 View Post
If the resistor is bad, it will always run on high, but may be burnt out for some or all of the lower speed settings. In that case it wouldn't run at all on some or all of the lower settings. I would guess that your switch is bad. Also, there is nothing in the engine compartment that would have any effect on this.

You know I didn't think so. It just seemed very strange that all of a sudden my fan speed isn't working and I find 2 wires unplugged in the engine bay.

Would these resistors be put in plane sight or do I need to remove the gloveboz or other parts?

Thanks for all the help guys! It's getting cold and I'm taking her on a 6-hour trip each way this weekend!
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Unread 10-29-2008, 05:48 PM   #12
Burnerman
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Passenger side, inside the Jeep, below the glove box, just above the vent grill in the heater box. you'll see a plug with some wires that plugs onto the ductwork. Un plug it and remove the 2 screws holding the resistor block in place.
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Unread 10-30-2008, 07:24 AM   #13
K_2
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Quote:
Originally Posted by Burnerman View Post
Passenger side, inside the Jeep, below the glove box, just above the vent grill in the heater box. you'll see a plug with some wires that plugs onto the ductwork. Un plug it and remove the 2 screws holding the resistor block in place.
Ok thanks. I'll try that this morning.
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Unread 10-30-2008, 07:46 AM   #14
K_2
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The only think I found is a 3-pronged plug. If that's it then I don't know what a resistor looks like.

I am thinking that it may be the switch. A couple of weeks ago I had a toggle switch burn out and cause a linkable fuse to blow. I then took the dash apart and the heat control unit out. I may have damaged something then????
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Unread 10-30-2008, 08:17 AM   #15
Que89YJ
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Blower

The purpose of the resistor block is to source current for the blower. A fuse is a current device that blows when current draw across a circuit is too high to protect wiring (most people think the fuses are to protect the electronic and electrical devices on a vehicle, by design the electrical components are considered expenable) If the fuseable link was blowing the most probable cause was the resistors because they are current devices. Check the resistor block.
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