A/C blower stopped working?

1999 LINCOLN NAVIGATOR
285,000 MILES • 5.4L • V8 • 4WD • AUTOMATIC
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RHENSONSR
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  • 2 POSTS
I have the Auto Temp Control panel. Pulled the plug on the motor, hooked up 12V and it spins great. Removed the regulator and checked the 3 wires coming from the loom and it had no voltage. 2 fuses and the relay are good. Is my next move to replace the dash control unit? Thanks
Jul 8, 2023 at 9:25 PM
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JACOBANDNICKOLAS
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  • 110,175 POSTS
Hi,

I attached a pic below from the wiring schematic. Let's check it this way. First, confirm the two fuses are good and have power to and from them.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Next, with the key in the on position, check pin 86 of the blower relay for power. If it has power, turn the HVAC on and see if there is a ground path provided by pin 85.

If that checks good, then check pin 87 for power. It should have power regardless of the key position.

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Do this and let me know the results.

Take care,

joe

See pic below.
Image (Click to enlarge)
Attached Media
Jul 9, 2023 at 9:11 PM
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RHENSONSR
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Thank you for your reply. I went to the yard and pulled a dash unit from a 2000 model, and it worked. Seems there was a problem in the head unit and thankfully my A/C is working again.
Jul 11, 2023 at 10:21 AM
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JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

Thanks for the update. I'm glad you were able to find one and it worked. And I agree. Something was likely shorted in the head unit.

Take care and feel free to come back anytime in the future.

Joe
Jul 11, 2023 at 7:39 PM