Classic questions

**BigJon** · 12th April 2018, 08:03 PM

Originally Posted by DoubleChevron

this dash

that big bulge above the passengers feet is a huge evaporator with two fans pushing air through it.

seeya,
Shane L.

I have that one. It is garbage. I have resorted to blocking the vents on the passenger side to try to get some air flow towards the driver's side. Still like an asthmatic blowing through a straw. Maybe I need to pull it apart and check for blockages.

**DoubleChevron** · 12th April 2018, 08:28 PM

Originally Posted by BigJon

I have that one. It is garbage. I have resorted to blocking the vents on the passenger side to try to get some air flow towards the driver's side. Still like an asthmatic blowing through a straw. Maybe I need to pull it apart and check for blockages.

Your fans must be dead. You need to put both the outer flaps down levers down (so you get recycled air only).... Then move the a/c lever all the way over. This should switch off the main heater fan, and kick the two fans build into the evaporator box into action. it flows a lot of VERY cold air. Mine isn't as cold as it was 6months ago, so I still have a slight refrigerant leak. That WILL be fun to find. You can't use leak detectors when your using bang gas as the refrigerant

You can:

a) Have a good laugh at my expense
b) See how HUGE and decent the A/C is in the rangie by looking here

Air Conditioning

I'm betting either one or both of your evaporator fans are not working.

seeya
Shane L.

**BigJon** · 12th April 2018, 08:31 PM

Fans are working. Makes plenty of noise, not much breeze.

**DoubleChevron** · 12th April 2018, 08:36 PM

Originally Posted by BigJon

Fans are working. Makes plenty of noise, not much breeze.

They aren't working properly. Does the heater fan turn off, then the two big barrel fans above the passengers feat switch on ?

**bee utey** · 12th April 2018, 09:06 PM

Originally Posted by BigJon

Fans are working. Makes plenty of noise, not much breeze.

Drop the fans off, you'll probably find a good layer of fluff from the foot well stuck on the evaporator. They're pretty easy to get to work well, those things.

**BigJon** · 13th April 2018, 09:07 PM

Originally Posted by DoubleChevron

They aren't working properly. Does the heater fan turn off, then the two big barrel fans above the passengers feat switch on ?

Yep

**PhilipA** · 14th April 2018, 08:16 AM

You should also check that the vacuum hoses to and from the vacuum storage "ball" under the bonnet are not cracked as this will put the air into the footwells rather than the face vents.

Regards Philip A

**DoubleChevron** · 14th April 2018, 08:53 AM

Originally Posted by PhilipA

You should also check that the vacuum hoses to and from the vacuum storage "ball" under the bonnet are not cracked as this will put the air into the footwells rather than the face vents.

Regards Philip A

pretty sure the hard dashes are all cable operated ?

**PhilipA** · 14th April 2018, 09:22 AM

pretty sure the hard dashes are all cable operated ?

No my 91 had vacuum operated flaps. I think it was an upgrade in 89 with the 3.9.
I also thought of something else about both the really old ones and the later ones. You have to be sure that the thermostat sender is not touching the fins of the evaporator but is close. They sometimes wander.

Regards Philip A

**Mercguy** · 14th April 2018, 10:23 AM

Originally Posted by BigJon

Fans are working. Makes plenty of noise, not much breeze.

Fans shouldn't make any noise - if they are, you have **** in the evap box and possibly brushes/bearings on the way out on the motors.

Shane's dead right on this - these HVAC units on 88-93 hard dashes are freaking cold as charity, and you don't need the fan on high to freeze to death, just on 1.

The Evap cores leak, as do the compressors. UNusual for a hose to go, occasionally the fittings do leak. Most of the time the schrader valves are the culprit - not uncommon for them to not be fully screwed in, and the cap covers can depress the pin. Even thought e covers have an oring, they are only meant to keep detrirus out, not seal gas in.

If you put dye in the system, you're likely to see it all over the evap fins after a while.

That's how I found mine. Cleaning that setup is a pain, but worth it.

I pulled all the ducting and cleaned it in the laundry tub with some napisan as well. clark rubber has the EPDM foam rubber seal material if you need to redo the seals.

It's not a 5 minute job, however it is worth doing, even if you find issues elsewhere and not in the evap core.

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