Heat/cool fan won't turn on?

2017 DODGE RAM
120,000 MILES • TURBO • 4WD • AUTOMATIC • DIESEL
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DAVENOOB
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My fan stopped working and I replaced a few parts. The console with the knobs, regulator, and fuse. I hooked 12v to fan and it works. Also the console with knobs isn't lighting up. I'm helping a friend who isn't internet literate so kinda going off what he has told me. Tomorrow we are going to run voltage meter and see if we can find where the power stops. I'm unfamiliar with this car. Besides running voltage meter and following power what else should I be aware of? I realize the regulator and front control console panel probably aren't the problem if properly installed. Big if anyways any heads up pointers would be great. From there I'll run tests and update/ask as needed. Thanks

2017 dodge ram diesel 2500 6.7
May 31, 2026 at 8:03 PM
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STRAILER
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So first I would check the power and ground to the blower motor this guide will show you how.

https://www.2carpros.com/articles/how-to-test-an-automotive-hvac-system-blower-fan-motor-a-detailed/

Most of the time the problem is the blower module or did you replace that and you called it a regulator? Also, there is a blower motor and a run 1 relay in the fuse panel under the hood. While you are there check the #84 fuse 15 amp. Here is the wiring diagram so you can see how the system works. Check out the images (below). Please let me know what happens.
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Jun 1, 2026 at 5:55 PM
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DAVENOOB
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He called the regulator the part that regulates the power for fan settings. Low 4volts, medium 6 volts and so on. Like I said once I get into the car I can give more info. Thanks for the start.
Jun 1, 2026 at 6:06 PM
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STRAILER
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Yep yep, let me know what happens
Jun 1, 2026 at 6:23 PM
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DAVENOOB
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Ok that diagram is past my knowledge level. Where's the run 1 relay located? I'll let you know.
Jun 1, 2026 at 11:35 PM
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STRAILER
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No worries, here is the location of both relays. Check out the images (below). Please let me know what happens.
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Jun 2, 2026 at 2:29 PM
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DAVENOOB
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Only one picture. Are both relays in same spot?
Jun 2, 2026 at 3:15 PM
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STRAILER
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They might be internal to the PDC. I would check for power to the dr/blu wire at the fan motor when the AC is on and running first. This guide can help

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester/

Please go over this guide and get back to me.
Jun 2, 2026 at 3:25 PM
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.