95 Civic A/C Troubleshooting help
cp___32
07-25-2012, 12:38 PM
Hey everyone!
I've been trying to troubleshoot my A/C issues with my 95 Civic DX Coupe and need some help. You'll have to bear with me, I'm going through some personal issues so my brain feels like it's in a blender and the solution might be staring me in the face but I can't seem to wrap my head around it.
I have checked all the fuses (both under the hood and the 7.5A under the dash) and all of them have power running through them. I've chased the voltage all the way to the relays and when the A/C button on the dash is clicked "On" the condenser fan engages, however the compressor clutch does not. I've switched the relays back and forth and verified that both relays work because either way I have them around, the fan engages and the clutch does not.
I can jump a wire direct to the clutch and it will spin up so it's not seized and will operate when supplied power directly.
The pressure switch you say? Well, I thought that too, so I pulled it. I'm not sure how to check it other than to make sure everything else works and if the A/C doesn't work, replace the pressure switch. A while ago I think I might have checked for continuity between the leads and it seemed ok. Anyway, I've jumped a wire bypassing the switch entirely to rule it out.
I had a mechanic friend check the pressure quickly even though he was super busy I think he said I had 50 PSI which should be good enough. Not sure if that's high pressure or low pressure side so take that fact as it is.
I did check and am getting 12V to both the White, and Black/Yellow leads on the clutch relay switch. So naturally I'm thinking if it has power where it should, then maybe it's a signal issue. I decided to start by checking the black/red wire running to the ECU. It's got continuity (audible using a tester with a beep) from the relay to the far side of the connector plug located behind the airbox. I decided to fire up the car, press the A/C button and check to see if power is getting through to that point. I put a probe into the wire just out the back of the plug on its way to the ECU, and used the negative post on the battery because it's there and it's definitely a solid ground. To my surprise, the clutch engages and the A/C system functions as normal?! When I disconnect the wire, the clutch disengages, and when it's connected again, the clutch re-engages (and has battery voltage).
What does this test tell me exactly? Do I have an issue with my ECU? Do I have a grounding issue? Where should I go from here?
Thanks for the help!
I've been trying to troubleshoot my A/C issues with my 95 Civic DX Coupe and need some help. You'll have to bear with me, I'm going through some personal issues so my brain feels like it's in a blender and the solution might be staring me in the face but I can't seem to wrap my head around it.
I have checked all the fuses (both under the hood and the 7.5A under the dash) and all of them have power running through them. I've chased the voltage all the way to the relays and when the A/C button on the dash is clicked "On" the condenser fan engages, however the compressor clutch does not. I've switched the relays back and forth and verified that both relays work because either way I have them around, the fan engages and the clutch does not.
I can jump a wire direct to the clutch and it will spin up so it's not seized and will operate when supplied power directly.
The pressure switch you say? Well, I thought that too, so I pulled it. I'm not sure how to check it other than to make sure everything else works and if the A/C doesn't work, replace the pressure switch. A while ago I think I might have checked for continuity between the leads and it seemed ok. Anyway, I've jumped a wire bypassing the switch entirely to rule it out.
I had a mechanic friend check the pressure quickly even though he was super busy I think he said I had 50 PSI which should be good enough. Not sure if that's high pressure or low pressure side so take that fact as it is.
I did check and am getting 12V to both the White, and Black/Yellow leads on the clutch relay switch. So naturally I'm thinking if it has power where it should, then maybe it's a signal issue. I decided to start by checking the black/red wire running to the ECU. It's got continuity (audible using a tester with a beep) from the relay to the far side of the connector plug located behind the airbox. I decided to fire up the car, press the A/C button and check to see if power is getting through to that point. I put a probe into the wire just out the back of the plug on its way to the ECU, and used the negative post on the battery because it's there and it's definitely a solid ground. To my surprise, the clutch engages and the A/C system functions as normal?! When I disconnect the wire, the clutch disengages, and when it's connected again, the clutch re-engages (and has battery voltage).
What does this test tell me exactly? Do I have an issue with my ECU? Do I have a grounding issue? Where should I go from here?
Thanks for the help!
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