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Hottest day of the year and blower craps out

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Old Jun 16, 2022 | 12:10 PM
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Default Hottest day of the year and blower craps out

The usual suspect, the harness, is perfect, undamaged and there's no voltage coming to it. The relay feeding the harness also has no voltage coming to it. So, it's a fuse right?....no such luck. The blower 30 amp fuse is good, the fuse feeding the control head is good, and the relay for the HVAC system is good. I'm at a loss. Is there another fuse or relay in the circuit I'm missing? Any ideas would greatly be appreciated.
 

Last edited by Broken Halo; Jun 16, 2022 at 12:17 PM.
Old Jun 16, 2022 | 12:38 PM
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Hot Damn, what a bummer. I won't be much help, but I do have a question.

Was it working and then died (maybe not working to full capacity and then died), or was it one of those situations where you turned on the AC and nothing?

Have you had time to trace the harness farther up?

How about the AC Diode. You know if the Diode is bad, the AC no worky.... In all my years I have never had one die on any of my vehicles, but they do not last forever.
 
Old Jun 16, 2022 | 02:00 PM
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Old Jun 16, 2022 | 02:03 PM
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It won't even blow on heat setting so that should eliminate anything with the A/C circuit. EVERY fuse in the fuse box checks good and I swapped a known good relay with the HVAC relay and still nothing. I'm going to try running a direct 12V+ to the harness that plugs into the blower resistor and see if the blower kicks on. The only thing I'm not sure of is there are 2 heavy gage orange wires on that connector. I'm sure one feeds 12v+ IN to the resistor and one is 12v+ coming OUT of the resistor to the blower motor. The other wires between the 2 orange wires are passing thru the resistor giving different voltages for different blower speeds. I just don't know which orange feeds directly to the blower motor. I don't think it should hurt anything if I pick the wrong one? If the blower fires up THAT should tell me that there's some problem BEFORE the relay and fuses that aren't providing power to them...BCM???
 
Old Jun 16, 2022 | 02:18 PM
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Update. Ran 12V + directly to the 2 orange wires from the resistor harness. One connection gave me a clicking sound under the dash somewhere (sounds like a relay activating) the other connection did nothing. No blower either way. I know THAT would sound like a bad blower motor since I ran power directly but that still wouldn't explain why there's no power going thru the harness to the blower. Must be something else in the circuit that activates the blower besides running 12v+ directly to the harness. Can't get an appointment at the dealership for 2 hot weeks.
 
Old Jun 16, 2022 | 02:24 PM
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Originally Posted by hummerz
Relay #87 Good, Fuse #82 Good, Fuse #69 Good. The clicking I heard up in the dash when connecting 12V+ directly to the resistor harness must have been the "High Speed Blower Motor Relay". Since connecting 12V+ directly to the harness and still nothing there must be a blower motor ground that's not making contact thru the BCM?....Just a thought.
 
Old Jun 16, 2022 | 02:36 PM
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Brown(BN) wire is B+ to the blower motor. Check connectors C11 C200 C203 B+ Brown

 
Old Jun 16, 2022 | 03:05 PM
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I thought ORANGE OG #52 coming out of the resistor harness was battery + ?......I checked all the brown wires shown in your picture and can't get 12+ out of any of them. I see the connector going directly into the blower motor (orange and brown). Are you saying the brown is pos. and the orange is neg? I was going to unplug THAT connector and try running a hot and ground directly to the blower motor but they sure made it hard to get to that connector.
 
Old Jun 16, 2022 | 03:08 PM
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Originally Posted by Broken Halo
I thought ORANGE OG #52 coming out of the resistor harness was battery + ?......I checked all the brown wires shown in your picture and can't get 12+ out of any of them. I see the connector going directly into the blower motor (orange and brown). Are you saying the brown is pos. and the orange is neg? I was going to unplug THAT connector and try running a hot and ground directly to the blower motor but they sure made it hard to get to that connector.
Leave it plugged in an back probe 12v to the BROWN wire. If it works you have a good ground.
 
Old Jun 16, 2022 | 03:12 PM
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Originally Posted by hummerz
Leave it plugged in an back probe 12v to the BROWN wire. If it works you have a good ground.
Already tried that at the relay connector (black connector) and still nothing.
 



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