A/C Blower motor relay

2004 JEEP GRAND CHEROKEE
118,000 MILES • 4.7L • V8 • AWD • AUTOMATIC
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ANDY BOYER
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Hi, my heat/air conditioner blower motor only works on high. I have replaced the blower motor relay. The problem was fixed temporarily (like one day), but now I have the same problem. I am not sure what my next step would be. Should I look at the blower motor itself? Sounds like I should also double check the new blower relay/resistor to make sure it is not defective? Thanks for your help.
Nov 10, 2016 at 9:57 AM
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KASEKENNY
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We need to suspect the blower motor controller is the issue on this type of problem. However, it could be the HVAC controller not sending the signal for the other speeds.

I am attaching the wiring diagram and we need to test the supply voltage coming into the blower motor controller. It should increase as the speed is increased.

I am attaching the process on how to replace the controller which is the most likely cause but we need to do this testing and go from there.

https://www.2carpros.com/articles/low-or-no-air-flow-from-vents

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-wiring

Let us know what you find and what questions you have and we can go from there. Thanks
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Dec 14, 2020 at 4:44 PM