A/C problem

[John]

My subaru is a 1995 Legacy L. The A/C works fine at highway speeds, but
when crawling along, only hot air comes hot. What would cause the A/C to
work only at high RPM's? The belts are new, so that is not the problem.

Any help would be appreciated.

John
(e-mail address removed)

 

[Edward Hayes]

I would first suspect a low charge because when driving slow the AC has less
through-put. eddie

 

[TM]

Are the 2 radiator fans turning when you turn the A/C on? Are the
radiators clean when looking at them from the front of the vehicle?

 

[Victor Roberts]

My subaru is a 1995 Legacy L. The A/C works fine at highway speeds, but
when crawling along, only hot air comes hot. What would cause the A/C to
work only at high RPM's? The belts are new, so that is not the problem.

Any help would be appreciated.

I agree with Bill, as I had a similar problem on my '97 OBW. If the
A/C works only at high ROAD SPEEDS you may have a problem with the
electrically operated fan that cools the A/C condenser and the
radiator. What does the engine temperature gauge read when you are
stopped in traffic? After I noticed that my A/C was not working in
traffic, I then noticed that my temp gauge was nearing the high end


In my case the problem was only a fuse that was blown when my son
drive the car through some deep water during a very heavy rain storm.
The water must have created a drag on the cooling fan and that blew
the fan fuse.

 

[John]

The engine temperature gauge has always been fine. It never gets near
overheating. I will have to check the radiator fans later.

John
(e-mail address removed)

 

[js]

You are right. One of the fans does not come on when the A/C is on. Should
both fans always come on together? Any suggestions what could be wrong with
the fan?

Thanks,
John
(e-mail address removed)

 

[TM]

Is the A/C compressor running and one of the fans is not working?

What I see in the Subaru Manual:

There are 3 relays in the Engine Compartment fuse box. These will be
identified in the fuse box cover lid. In any case they are shown to be
the 3 closest to the engine and closest to the front of the vehicle.

There are two fuses, in front of the relay closest to the front of the
vehicle that are directly related to the functioning of the fans. The
20 amp one works with the the main, engine cooling fan. The 10 amp one
has to do with all the relays for the fans.

SBF4, in the same box, controls the ignition to all relays.

There is also a Diode element. Its connector is orange. I am not sure
about the location but it seems to be behind the drivers side, left
strut tower. This one seems to work with the main fan.

In the in cabin fuse box, fuse 13 is related to the secondary fan. In
the same box, there is a relay, the top right one, that controls the
secondary fan low speed.

Finally, the ECM deals with the fan for the engine cooling and the A/C
compressor relay.

The fans themselves are 2 speed fans. With the A/C compressor on, both
fans should run at max speed, meaning, all wires but ground, should have
12 volts.

For the main fan: Black is ground, Yellow/Red is high speed, White/Blue
is low/high speed.

For the secondary fan: Black is ground, White/Green is high speed,
Yellow/Red is low/high speed.

I hope this info helps and I wish you good luck.

TM

 

[John]

Yes. The compressor runs and the left fan does not.

Thanks for your help. At least I know where to start.

John

 

[Victor Roberts]

The engine temperature gauge has always been fine. It never gets near
overheating. I will have to check the radiator fans later.

Do you have separate fans for the radiator and A/C condenser? In my
'97 OBW the A/C condenser is mounted in front of half the radiator.
When the cooling fan for the A/C condenser and radiator failed, not
only didn't the A/C work in traffic, but the car overheated also. In
my case, both the engine overheating problem and the A/C problem were
"solved" (temporarily of course) by driving a mile or so at 50 MPH or
so.

 

[John]

Thanks for your help. After all the trouble, it turned out to be a fuse.
I should know to check there first.

John