No AC blowing, No Heat blowing, hear hiss when turning on AC or heat

lincoln
towncar

#1

I turn my car on. I have no error lights on my dash. The heater and AC control unit lights up. I press the down arrow on my in-dash heater/AC control unit so I can get some cold air. I hear a hissing sound for about 2 seconds, but no air comes through the vents

I get the same effect when trying to use the heater. Quick hissing sound, no air through vents.

Both stopped pushing air at the same time (when my ac stopped working, I tried to put out heat just to check)

I have checked al the fuses under my steering wheel and in the engine compartment using a circuit tester (w/light).

There is an AC Clutch relay fuse in the engine fuse box. Not sure if I should check that.

What should my next steps be. please be as specific as possible (pictures are always helpful).

Thank you.


#2

Add what year, engine, mileage when you get a chance; that will help with the diagnosis. If I were to guess, the main thing the heat and A/C have in common is the fan motor. If it is not working, you won’t feel any air blowing. This may also explain the hiss you are hearing-probably vacuum actuated doors to change direction of air flow-you just may never have heard this since it would be drowned out by the noise of the fan motor.


#3

2001, V8, 120k miles


#4

The HVAC system in your vehicle is totally electronic. No vacuum motors.

And when the HVAC system in your vehicle fails to produce cold/warm air, it’s usually caused by a defective EATC control module.

https://modulemaster.com/rebuilds/shop/comfort/climate-controls/ford-lincoln/

Tester


#5

@Tester

I will perform the diagnostics listed here and post the results:


#6

It was the blower motor/regulator. I took out the fan and hooked it directly to the battery and it worked.

I then tested that power was getting to the blower motor from the wires.

So I went to AutoZone and purchased a replacement blower motor/regulator and it all worked once it was hooked up.

Now my car gets comfortably hot and the AC works, though not as cold as I wanted.


#7

Thanks for a post back, good to know what worked, and that you got your car’s climate regulated again. Best of luck.