MadVladCivic

I have a similar issue w/ the a/c. It happened while driving out
of DC this morning. The a/c has not been the coldest but it was cool.
Currently, it is blowing hot air when the a/c is engaged and
the re-circ button is not selected. Feels like ambient temp when
the re-circ button is selected.

The a/c compressor pulley is spinning and the belt appears to
have sufficient tension. The large refrigerant line is hot to the
touch but not scalding. The small refrigerant line is neither cold
(cool) nor hot. It is ambient temp.

The system has never been serviced. 96 Honda Civic DX 2-door.
101k miles.

Thanks

MadVladCivic

Follow up.

I take it that the condenser fan should activate when the a/c
button is selected. The green light on the a/c button illuminates but
the fan does not activate. Ran for about 10min and got the radiator aux cooling fan but no condenser fan.

Pulled the 20amp condenser fan fuse in the engine bay fuse box and
it was toasted. I would like to pick up a few extra fuses rather than
simply subbing one of the other 20amp fuses in the event that
the reason for the blown fuse is still evident.

Thanks.

Former User

Which specific fuse was blown?

Swap the fan relay and compressor relay in the hood fuse box. Does the condenser fan now run?

MadVladCivic

I believe the label was "condenser fan" fuse. 20 amp in the engine bay
fuse box. It was the fourth fuse from the left of five fuses in a row
along the upper edge of the fuse box (closest to the firewall).
I don't have my service manny handy as I'm out of state.

I was going to substitute another 20amp fuse but was concerned
that if that blows... Will pick up some new 20ampers tomorrow.

BTW, two points immediately suggest themselves:
1) if the new fuse blows immediately/quickly, what does that indicate?
2) if the fan runs but still does not solve the issue, what's next?

Thanks

Former User

20A Fuse 56?

It supplies voltage to both the condenser fan and compressor clutch.

Unplug the fan or the compressor clutch. Which unplug prevents fuse 56 from blowing?

MadVladCivic

OK, I see what you did here.

http://troubleshootmyvehicle.com/hon...fuse-relay-box

Relays labeled A and B.

Former User

...

MadVladCivic

Yes, 20amp FUSE# 56. Toasted. Will get a new fuse(s) tomorrow.
Yes, its labeled condenser fan/AC clutch.

So, in summary:
1) Will put a new fuse in at #56: Does fan run? Y or N
If N and new fuse has not blown, then:
2) Play switcharound w/ A and B relays: Does fan run? Y or N
If N, look for new angle.
If fuse continues to blow, then:
Unplug the condenser fan or compressor clutch etc

Thanks.

Former User

For (1), also check whether or not compressor clutch engages.

MadVladCivic

How to check this? Is it an audible cue?

Former User

There is a click when the field coil pulls the armature plate against the pulley. However, when the clutch is disengaged, the armature does not spin with the pulley, whereas it does when engaged.

MadVladCivic

Got it. A blown fuse #56 would explain why I saw (and heard) no
spinning other than of the a/c compressor pulley itself.
OK. Will run all these tests tomorrow and report back later.

Thank you for your assistance.

MadVladCivic

Hi RonJ,

OK. Removed BOTH relays (a/c compressor clutch & condenser fan) prior to replacing fuse #56. After replacing fuse, I plugged the condenser fan
relay into the condenser fan relay slot. GOT and MAINTAINED fan upon
activation of a/c button. Then, I plugged the a/c compressor clutch
relay into the condenser fan relay slot and GOT and MAINTAINED fan.
CONCLUSION: both relays are good and the fan appears to be good.

Next, starting from both relays UNPLUGGED, I plugged the a/c
compressor clutch relay into its slot. BAM! Got blown fuse.

But it seemed like a disc was turning w/ the a/c compressor belt pulley.
The disc is btw/ the pulley and compressor body. Is that the armature?
How is that possible if it requires an intact fuse to draw current?

OTOH, its possible that the fuse blew after I plugged the condenser fan
relay into its slot and tried running both components at once.

Former User

Ohm test the field coil part of the clutch.

MadVladCivic

My bad. The surfaces that are spinning are simply the pulley. The armature plate turns w/ some resistance when I pushed on it w/ my index finger.
But it is not lose, eg, does not wobble.

Don't have my multi-meters w/ me!

So, I take it that we have narrowed it down to the a/c compressor....

True or False:
Now we test to see if the issue lies w/ a replaceable COMPONENT in
the a/c compressor vs replacing the ENTIRE compressor itself.

Former User

The field coil is replaceable. Ohm test it when you have time.

MadVladCivic

Hi Ron,

Just found a multi-meter! Free Harbor Freight stuff you know!

Will test it right now.

Thank you again for your assistance.

Former User

My favorite store.

MadVladCivic

Hurricane Arthur pre-empts my testing.

I got the 8mm bolt out of the thermal protector, which freed the
field coil electrical connection. Its wrapped in a black rubber sleeve.
How do I separate the connector wo/ damaging the circuit especially
where it feeds into the coil? Based on the diagram, it looks like
it simply pulls apart. Do I need to cut that sleeve?

Former User

...

MadVladCivic

Hi Ron,

OK. Got the electrical connector separated. I'm using the 200 ohm
scale on the Harbor Freight multi-meter. The red lead to the connector
terminal and the black to the a/c compressor housing. If everything
is compatible, the meter reads "1", which is indicative of "off scale".
Thus, it would appear that the field coil is bad.

Former User

The "1" means infinite resistance, which if the test were done correctly, indicates an open in the coil circuit. However, this test outcome is the opposite of what was expected. A bad field coil that is causing fuse 56 to blow should yield an Ohm reading below spec, that is lower than 3.05 Ohms.

Redo the Ohm test and also post pictures of you doing the test. Make sure you are testing the correct end of the field coil connector. See diagram in post #16 - Checking Field Coil Resistance.

If your Ohm test holds up, however, then the next step would be to test the compressor clutch red wire for a short to ground.

MadVladCivic

Hi Ron,

No ability to post pics here. My wife didn't come this trip!

OK. To be sure: The connection btw/ the a/c compressor and
the thermal protector has been separated. Thusly,
I am touching the red probe to the male part or it appears to be the
male side of the connection. Clearly not touching the thermal protector
side of the connection. And the black probe is touched to a bolt
on the front of the a/c compressor housing. Think its a housing bolt
as there are several

Multi-meter set for resistance (5 possible selections from 200 to 2000K
ohms). The lowest scale (200 ohm) is selected. It was tested across
a new piece of 18g wire and registered 1.8 ohm. Stable reading.
This meter is brand new. First time use.

Harbor Fright multi-meter is the "Cen Tech 7-function multi-tester."
Catalog # 98025.

I will test again.

There is actually another post from 2009 or 2010 in which the poster
posted some pics. They show the area we are discussing, eg, the
thermal protector connection to a/c compr. Will try to find after lunch.

Thanks again and Happy & Safe Fourth.

Former User

Sounds like you're doing the field coil test correctly with the multimeter on the proper setting, though I can't verify without pictures. Try using a different ground point on the compressor (use a different bolt or the housing of the compressor).

While the compressor clutch is disconnected from the circuit, you can do some additional simple tests. Install a good 20A fuse into the #56 slot and remove the fan relay but leave the clutch relay plugged in. Start engine and turn on A/C. Does fuse 56 no longer blow? If so, re-install the fan relay and repeat test. Post the results.

MadVladCivic

Hi Ron,

OK. Ran several more multi-meter ohm tests touching the black probe
to a diff housing bolt and then the housing itself. Infinite resistance.
Touched the red probe to diff sites on the male metal connector as well,
eg, outside, inside the "tube", etc. Re-confirmed that the multi-meter
is working w/ the 18g wire.

OK, let me clarify: Remove fan relay. Keep a/c comp clutch relay
in position. While a/c compressor is disconnected at the thermal
protector, turn on engine and select a/c. If fuse has not blown,
then re-insert fan relay and repeat w/ BOTH relays are in proper
place?