Honda_San

Hello HT,

I have tried searching this issue but cannot seem to find a thread that has ended with a solution to any similar problem.

I have a 95 civic ex coupe. I have been having an issue with the a/c in this car. What happens is this: when the car has been allowed to sit in the sun for a while and get the interior good and hot, the a/c does not engage. This is to say the compressor clutch nor the condenser fan cut on. I have charged the system with the correct amount of refrigerant with the machine we have at work. It has not leaked out. If the interior of the car is allowed to cool off, the a/c will start working and usually keep working. Every now and then it may cut back off, but this really seems to be happening with the interior being hot.

I have already replaced the climate control, tried swapping a/c compressor clutch and condenser fan relays around, as well as substituting a new one in, and replaced the climate control harness from the control itself down to where it plugs in behind the cigarette lighter to the rest of the body harness. Also the blower motor resistor.

I have tested continuity at the relay with the a/c button on and the system not operating and I am getting no signal at the relay when the a/c is not wanting to work. Keep in mind that when I press the a/c button on the climate control I am always getting the green light indicating the button is pressed. This seems strange to me as I am "magically" getting that signal when the interior cools down. I have tested voltage at the a/c thermostat behind the glove box and I have voltage at pins 1 and 3. If I ground pin 2, the a/c will come on and function as it should.

Any help would be appreciated. Sorry if this post sounds choppy at all, but I am becoming pretty frustrated with this issue as I cannot understand what is making it come on and work fine and then not work at all when I need it most! Thanks in advance!

Honda_San

I have followed the following flow chart:




Fuses 13 and 35 are ok.
The place I ended up at the flow chart was to replace the heater fan switch. I am assuming I did this in putting in another climate control?

Former User

Which relay? Continuity between which terminals? What do you mean by "signal"?

When the A/C button didn't work to turn on the A/C?

Not sure what you mean here.

When the A/C button didn't work to turn on the A/C?

Former User

Did you do ALL tests in the flowchart when the A/C button didn't work to turn on the A/C?

94eg!

iTrader: (2)

You probably won't be able to test for the problem unless the components are 120 degrees or more.

My 94 CX does the same thing. I think it's a bad solder joint behind the AC button. I found if I popped off the AC-button cover and jammed the pointy end of a wooden kabob skewer into the hole, it worked again. I stick it in above the circuit board and it presses down on it slightly. Then the compressor kicks on again. I was planning on either taking the unit apart & re-soldering all the connections, or buying a new heater control unit. For now I just keep the 2" pointy end of the skewer in my ash tray for when I want AC.

Honda_San

Which relay? Continuity between which terminals? What do you mean by "signal"?

The compressor clutch relay. I tested for the a/c request signal and that was not present when the a/c button on the climate control had been pressed.



When the A/C button didn't work to turn on the A/C?

Yes


Not sure what you mean here.

I meant that I get an a/c request signal when the interior has cooled off but not when its hot. "magically" was my frustration showing haha!



When the A/C button didn't work to turn on the A/C?

When I ground pin 2 on the a/c thermostat the a/c will come on regardless of the button on the climate control being pressed.

94eg!

iTrader: (2)

The problem is the signal getting to the relay. The light on the button has it's own ground. This means the signal path & light path are independent. The light being on means nothing in relation to the signal.

Honda_San

Now that I went back and read it I need to test the a/c button 22-15. I will get on IN and pull that one up now

Honda_San

Yes this seems to be what the problem is. I'm guessing it may be likely that both of my climate control units are bad. It seems like once the components start cooling off I can move the 16 pin green connector around at the climate control and the a/c will come on and work normally, as long as I hold it in the right position.

Former User

I would try this^ first.

Honda_San

I'll get started taking it apart now

Former User

So what exactly did you test for? On which relay pin or wire?

How do you define signal? What's the test and on what wire or pin?

This^ is normal. What was the result when the A/C button didn't work to turn on the A/C?

Former User

Not sure what test you're talking about here.