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Discussion Starter · #1 ·
Hello, a little over a month ago I was driving with my AC on and heard a terrible noise and then a clicking for about 30 seconds after and then nothing. After that I had no blower at all. I finally got around to looking at it today and found a nice chunk of plastic that broke off somewhere in the venting and must’ve jammed my motor. It blew the large 40 amp fuse under the hood but no other hvac fuses. I replaced the fuse and the motor ran again but only on full speed and wouldn’t shut off without pulling fuse. I then replaced and spliced in a new relay/resistor but still having the same issue. I tapped on the relay to see if the contacts welded but got nothing. Where should I look next? Thanks for any advice.
 

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Vehicle info please.

And, is it a manual system, or the automatic system?

And what relay are you tapping?
 

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EB, it would be good to include year, model and engine to help the guys here help you. I see in your user it says 1500 hd but no other info. Ray beat me to it.....
 

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Discussion Starter · #4 ·
My bad was almost having a heat stroke while typing that and totally forgot. It’s a 2003 1500HD with automatic climate control or the “CJ2” version. I was tapping on the resistor that I replaced near the blower itself. Thanks sorry about that
 

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No prob about the truck info.

The part you were tapping on was probably the transistor that varies the speed.
Rock Auto says you have a relay under the hood, in the fuse box. It may have overheard and melted.
 

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Discussion Starter · #6 ·
Hm, I’m not seeing anything related to hvac or blower for a relay under the hood or inside the driver door fuse boxes. I always thought the relay was part of that transistor near the blower.
 

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Me too, just going by Rock Autos website.

And, as far as I know, the relay/resistor assembly is only for the manual HVAC.

I see if I can find a wiring diagram
 

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Ok, the wiring diagrams that I found do not show a relay under the hood, I don't know what Rock Auto was on about.

The auto HVAC uses a transistor to control speed instead of the relay (high speed) and resistor pack (all other speeds) that the manual system uses.

Usually the problem your having occurs because the speed control transistor fails; but you said you changed it.
I re-read your post, you said you replaced and spliced in the new speed control module; but then you said you tapped on what you thought was the relay.
That statement makes me think you spliced in new wires, but reused the speed control module, can you confirm what you did?

If you replaced the speed control module, I'm guessing there may be a melted wire your not seeing.

But let me know, we'll get it fixed.
 
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