MATiC

ok so this is how the story goes.
i got this car last year, and the a/c worked perfectly.
however, the a/c line that runs in front of the condensor and radiator somehow cracked at a bend and of course everything leaked out of it.

so, here are where the problems start. replaced the line and the receiver dryer. i hooked up the gauge manifold set and vacuumed out the system. let it sit overnight to make sure that vacuum held and it did. i noticed that the a/c button is no longer illuminated (it was pushed in, "on" position). i found it odd, but figured maybe the small bulb had blown and began filling the system with freon.

the low side pressure quickly started climbing but the a/c compressor and condensor did not fan come on. now i've refilled a/c systems before and i know that this should happen but it didnt. i tested the condensor fan and compressor and they both work when connected to a 12 volt source. so i figure they're good. i'm starting to believe that the issue begins with the a/c button. any input?

Former User

Do you have an R12 or R134a system?

Is 20A hood fuse 35 or 7.5A dash fuse 13 blown?

MATiC

it's an r12 system converted to r134a.
when i replaced the receiver drier and ac line, i emptied and reoiled the compressor with pag oil.

neither of the fuses are blown.

Former User

Unplug the pressure switch and then ground the Blu/Red wire in the connector. When you turn the engine on, now does the A/C fan run and does the compressor clutch engage?

MATiC

just tried grounding the blue/red wire and started the car with ac button on and motor blowing. neither the compressor clutch or condensor fan kick on, but the engine does rev itself slightly.

Former User

Does installed 20A hood fuse 35 have voltage to body ground at BOTH of its top test tabs?

Do the same test for 7.5A dash fuse 13.

MATiC

yes there is voltage at both test points on both of the indicated fuses (somewhere around 12 volts)

Former User

Unplug the fan relay from its connector. In the free connector:

1) Jump the white wire to the Blu/Blk wire. Does the fan run?

2) Turn the key to ON(II) and then jump the Blk/Yel wire to the Blu/Blk wire. Does the fan run?

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Unplug the compressor clutch relay from its connector. In the free connector:

1) Jump the white wire to the red wire. Does the compressor clutch engage (click)?

2) Turn the key to ON(II) and then jump the Blk/Yel wire to the red wire. Does the clutch engage?

MATiC

fan relay connector:
white to black/blue: starts fan
key on, blk/yellow to blk/blue: starts fan

compressor cluth relay connector:
white to red: compressor clicks
key on, blk/yel to red: compressor clicks

these relays were my first thought, and i bought new ones to replace them.
so both relays in these connectors are new.

Former User

Turn key to ON(II), unplug the pressure switch, and then:

1) measure voltage to body ground at the Blu/Red wire in the pressure switch connector. Voltage?

2) unplug the condenser fan relay and again measure voltage at the Blu/Red wire in the pressure switch connector. Voltage?

3) replug the condenser fan relay, unplug ECU connector B, and again measure voltage at the Blu/Red wire in the pressure switch connector. Voltage?

MATiC

1: 4.66 volts
2: 4.66 volts
3: 0 volts

jestin91

for me it was the switch push the a/c buton in kinda hard or the outhe 2 next to it

MATiC

i'm THINKING it's the heater control panel itself (primarily the ac button)
like i said, it used to be illuminated when i pushed the ac button on.
now, it won't turn green when it's pushed in so maybe that means something.
also, just reading, this model civic is notorious for the panel going bad.
but before i jump to any conclusions, i'm hoping that RonJ has some more troubleshooting tips

MATiC

another question:

my buddy recently replaced the receiver drier in his civic (98). we connected the gauge manifold set and vacuum pump to it and oddly enough it pulled vacuum (-28) within a minute or two. i found this very odd. closed the hand valves on the manifold set and turned off the pump. let it sit for 15 mins or so and vacuum held. what gives? thermal expansion valve stuck closed maybe?

Former User

Voltage is not coming from the condenser fan relay to the Blu/Red wire in the pressure switch. That's the problem.

Are you sure fuse 13 is fine?

MATiC

i went and replaced fuse 13 with another 7.5a fuse and still nothing so i'm positive the fuse is good. i tested both of them (old one and new one) and they're both fine