98 Pathfinder no AC

[llamuh]

I'm new here but I know with most forums the first response is, "read the stickies!" or "have you tried the Search feature?" so I've done both of those first.

I have a 1998 Pathfinder with AC issues. A year or two ago, the compressor was barely turning so I got the whole thing replaced. The AC worked great for the first year or so and then I basically stopped driving the vehicle for a few months as it is just a secondary vehicle. This past spring I started driving it more often and the AC blew nice and cold. The vehicle sat for another month or so and when I went to drive it again, I found that the AC doesn't blow cold at all. The blower is working fine and blows at variable strength/speed depending on what the dial is set on, as it should.

The compressor appears to be turning with no issue and I do not hear any odd noises. The little light on the AC button comes on, however I noticed something odd. When I turn the AC on and off via the AC button (with the fan turned On to whatever setting) I can't "tell" that the AC is on. What I mean is that in most car's I've been in, including the Pathfinder, there is a different sound from the motor and the idle RPM changes when the AC is turned on and off, I assume from the load on the motor. I can also normally feel the difference if I turn it on/off while accelerating. The fact that this isn't happening makes me think the issue is electrical rather than all of the refrigerant suddenly leaking out.

I changed out the fuse (one under the hood on driver's side) with a known working fuse but it had no effect. I saw a connector with two wires going into it that seems to plug into the top of the compressor, so I took it off, stuck some small electrical wire into each hole in the clip (probes wont fit in the connector holes), and attempted to test it with my multimeter. I could not get a reading off of it whether the AC button was on or off. I'm assuming that I should read some sort of voltage from it if it was working correctly..

Any ideas on something else I could check? I know summer is almost over but it is still pretty hot here and I'd like to have it working. Any input would be much appreciated.

[Towncivilian]

Try swapping the A/C relay with another one of the same color.

[llamuh]

Is the relay the part that I called a fuse? (large blocks in a box under the hood on the driver's side)
If so, it is blue and I swapped it with another blue one and it had no effect. It would make sense that this was indeed a relay rather than a fuse. Maybe I should be looking for a fuse?

[Towncivilian]

Yes, the blue item you swapped out is a relay.

Do you have the automatic climate control, or manual knob-type controls?

[llamuh]

Manual knobs with a rectangular button to turn the AC portion on and off.

it looks just like this:

[Towncivilian]

Can you try following the diagnosis procedure described on page HA-151 of the factory service manual as best as you can?