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J

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Discussion Starter #1
Hello everyone. I'm from Arkansas and I have 2 Awesome Ford diesel trucks , 02 F350 7.3 Super Duty and a 05 F250 6.0 Super Duty. I need some help with my 02 7.3 a/c system. It started to blow warm air after driving for a little while and now it doesn't blow hard either ? I need help because its HOT in Ar. Thank you for any advice.
 

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Maybe a combination of things.
Start simple with checking all the fuses and swapping relays around.
The fan motor could have died, or the motor resistors could have burnt up.
Now it's not blowing at all? Or just not out the vents?
First need to figure out why it's not blowing, then can figure out the cooling.

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J

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Discussion Starter #3
It blows like it's on the lowest setting. And sometimes it blows hard and cold ? It's like it has a mind of it's own. I've checked relays.
 

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Probably the resistor going out.
You may also have a refrigerant leak.


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J

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Discussion Starter #5
Sorry I haven't been back in a little while but I've been super busy with work. I'm blessed to have an 05 6.0 that runs great (after bullet proofing ) to drive and has COLD a/c so my 02 7.3 has been sitting for a while. I started back working on it this past week and I found out a few things. I have power to the blower motor but blower motor does not run. I do not have power to the resistor ? I have swapped around relays and checked every fuse. I have 3 relay boxes under the hood on the driver side but I can't find anything to tell me what these go to ? I bought a new relay and moved it around in the ones under the hood but still nothing ? I can't figure out why I don't have power to the blower motor resistor? But have power to the blower motor right next to it ? I have nothing in the cab now. No air blows anywhere. HELP PLEASE. I'll be working on it today until I get it figured out or go completely NUTS trying !!
 

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Iirc, the resistors are on the ground side.

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I guess I'll replace the blower motor next ? One of the relays under the hood gets pretty hot while the truck is running ?
 

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Sounds like the A/C compressor to me. I replaced mine last year wasnt difficult at all to do. You should check the fuse for the compressor before you do anything. When and if you replace the compressor, make sure you have a shop remove the old fluid and replace it with new. The worst thing you can do to the system is use the cans you buy at the auto parts store.
 

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Sounds like the A/C compressor to me.
Hopefully, he has fixed this since it was posted last July. Still, I'm curious. How would an a/c compressor affect the blower speed? You've got some insight I can't quite follow and since I do a/c work almost daily, I'd appreciate the education.

When and if you replace the compressor, make sure you have a shop remove the old fluid and replace it with new. The worst thing you can do to the system is use the cans you buy at the auto parts store.
Old fluid? Do you mean the PAG oil or the refrigerant? What's wrong with the "cans you buy at the auto parts store"? I buy my R134a in 25 pound canisters, but I've used hundreds if not thousands of parts store cans of refrigerant and never had an issue with any of them.
 
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