Ventilation system not working

2002 MERCURY MOUNTAINEER

140,000 MILES • 4.6L • V8 • 2WD • AUTOMATIC

TXPROUD

MEMBER
1 POST

Was driving and the head unit to the ventilation system (AC and heater) lost power, including the rear AC. I have checked every fuse in the cabin and under the hood and they all seem fine. Am I missing a fuse or relay somewhere?

Jan 10, 2018 at 7:39 PM

STRAILER

✓ASE Certified Mechanic
54,832 POSTS

Hello,

There are several fuses that run the system and a blower motor relay.
Here are guides to help us find the problem:

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

Check for power at the fuses as well.

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

Below are the air conditioner wiring diagrams and the fuse panel location see where you are losing power.

Please run this test and get back to us.

Cheers, Ken

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Professional Diagram for 2CarPros Members
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Jan 12, 2018 at 12:03 PM