A/C help

[duke9074]

Hi guys im new here and hoping to find a new home as a new civic owner. I purchased a use 03 civic lx this winter and come to spring i have found out the a/c does not work. So far i have done the following i can jump the compressor and condenser fan on showing that they both do work. I have checked number 1 fuse under hood and number 14 fuse under dash, both are good. I have replaced the head unit (if you will call it that) inside the dash. I have tested the pressure switch for continuity and tried to jump it with negative results. Back in the fuse box i also have tested all relays found all relays to be good, they were bench tested by jumping terminal 3 and four with a battery and measuring voltage over 1 and 2. I check the pin in the fuse box for the relays with these results fan relay terminal 1 is zero volts terminal 2,3,4 all have 12v, compressor clutch relay terminal 1 is 0v 2 and 3 12v and terminal 4 is 0v. This terminal four also shows no continuity to ground or power. Thermal protection switch shows continuity. At this switch when the red and blue /white wire are jumped the system turns on as soon as the key is turn on and with engine running the system does work, except that the a/c button is in the off phase and when switch to the on phase the system turns off, kinda like its reversed with this jump in effect. I have read the other post about checking the ecu and mcu but unfortunately my wire colors are different in these and i do not know if the same pin number is accurate. If any one has any ideas for me or any direction to run i would appreciate the thoughts, i am puzzled by terminal four in the clutch relay, and the system working when jumped but in reversed. Thanks again for your time reading my post..... Andrew


Added note headunit (heater control panel) self diagnostic test comes back with no DTCs
Low pressure side has 35-40 psi, i do not have a gauge for the high pressure side

 

[RonJ]

Thermal protection switch shows continuity. At this switch when the red and blue /white wire are jumped the system turns on as soon as the key is turn on and with engine running the system does work, except that the a/c button is in the off phase and when switch to the on phase the system turns off, kinda like its reversed with this jump in effect.

It's unclear to me what two wires you are jumping. Please post some clear pictures. In my circuit diagram, the thermal protector on the compressor only has a single Blu/Red wire attached to it. Are you actually referring to the A/C pressure switch, which has Blu and Blu/Wht wires in its connector?

 

[duke9074]

The wires are the 1 and 3 terminal on the connector just above the ac compressor here is a picture the blue/white an red...
I will add a picture when I get home from work

 

[duke9074]

picture this is the only way i could figure out how to upload a picture. BY using a url link can u not add attachment photos to the text on this forum?


http://lh5.ggpht.com/_wLCc6cdE13M/TBHDt864m6I/AAAAAAAAKSw/NuGB3YSk7hU/IMG00164-20100610-2157.jpg

If i jump the top red wire and bottom wire which is a little blurry here but is blue with a white stripe together then that is when i get the system to be on with key on and functioning when the car is running but turns off when the ac switch is on.


Note RON J upon inspecting your wiring diagram i believe that there must be more wires than shown because if not that would mean i am jumping the relay terminal number 4 to ecm red wire to the power coming out of the pressure switch. This would make terminal 3 and 4 both hot on the relay?

 

[RonJ]

Upload pictures to PhotoBucket and then paste the IMG code into you post.

It's hard to tell what color the three wires are. Is the middle one Blu/Red? Is it a solid red wire to the left and a Blu/Wht wire to the right?

None of my circuit diagrams shows a 3P connector in the A/C system. Do you have an aftermarket A/C system?

Can you pan back in the picture to give an idea of where this connector is and what it plugs into? Does it connect to the pressure switch on the receiver/dryer?

Can you also post pictures of where the wires run to?

 

[duke9074]

it is a late year 2003 possibly has 04 wiring i bleieve 01-05 to be the same the wire colors u gave are correct the middle is blue and red solid red to the left and blue and white to the right. The connector clips to the side of the radiator fan housing located in the front drivers side and the 3 pin connector goes down the the a/c compressor. the other side of this connector had 3 solid red heavier gauged wires. The pressure switch would be located towards the drivers side about 6 inches from this connection, and the pressure switch uses a 2 pin connector with a blue wire with a dashed white line and a red wire with a dashed white line. A/c is facotry equipped the car has been family owned since new i purchased it from my father who owned it since 2003 no mods ever bone stock.


If need i can give any further clarification but can not find this in a wiring diagram either.

tomorrow am i will remove the wire loom and try to trace wires back to a location...

http://www.autopartswarehouse.com/details/QQHondaQQCivicQQ4-SeasonsQQA-fs-C_CompressorQQ20032005QQFS77613.html

thisisi where the other half of the conenctor goes to in my car

 

[RonJ]

The pressure switch should have a Blu wire and a Blu/Wht wire. Post a picture of what you think is the pressure switch and its connector.

Question

When you jump the Red wire to the Blu/Wht wire in the 3P connector and the A/C blows cold:
1) Does the condenser fan run?
2) Do you need to turn on the cabin blower or does it run by itself?
3) Does the A/C button light on the dash control panel turn on?
4) If you unplug the A/C pressure switch, does the A/C still work when you jump the wires?

 

[duke9074]

in the first diagram you have posted in previous post the a/c pressure switch its 2p connector located on the top of item number 5. Its 12 midnight and a picture of my actual car wouldn't come out well enough to show you. I will take photos in the morning before work....

When you jump the Red wire to the Blu/Wht wire in the 3P connector and the A/C blows cold:
its does blow cold then again it is roughly 45 degrees out in NY right now so very hard to tell.....

1) Does the condenser fan run? When jumped both fans condenser and radiator fan run as soon as key is cycled

2) Do you need to turn on the cabin blower or does it run by itself? Must be turned on by it self ( i beleive i will double check in the am)

3) Does the A/C button light on the dash control panel turn on? When light is off system runs when button is depressed light on the sytem turns off by this i mean compressor clutch disengages/ rad and condensor fan turn off

4) If you unplug the A/C pressure switch, does the A/C still work when you jump the wires? Have not tried this........

 

[duke9074]

pic and explanations please bare with me

general panned out view of the location i am talking about the switch is directly down in this image from the pressure line on the power steering pump
http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acimage.jpg

same view but labeled
http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acimage1.jpg

box toward drivers side or towards belts says ac pressure switch box closer to low pressure inlet says connectors location

this is the a/c pressure switch next is the wire connected to it
http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acimage1.jpg#!oZZ3QQcurrentZZhttp://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acphotoagian.jpg

A/c pressure switch wires
http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acimage1.jpg#!oZZ2QQcurrentZZhttp://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acpressure.jpg

now this picture is the connection getting jumped when removed from its clip location PLEASE AND I SAY PLEASE REMEMBER THE WIRE COLORS ARE OFF HERE I HAVE REPLACED THE CONNECTOR AND SOLDERED THE WIRES TOGETHER AFTER FINDING A OPEN INTERNALLY IN THE CONNECTOR. I WILLL EXPLAIN WIRE COLORS. Center wire remains unchanged blue with a red strip right wire in this photo solid red wire is now shown here as blue with a white strip, and the blue with white strip is now shown as a white with blue strip.
http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acimage1.jpg#!oZZ1QQcurrentZZhttp://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acpressure-1.jpg

here is a photo just behind the connections, you can see the fresh tape on the right this is where the connections were made.
http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acimage1.jpg#!oZZ4QQcurrentZZhttp://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acphoto2.jpg

update
2) Do you need to turn on the cabin blower or does it run by itself? Must be turned on by it self ...... this was verified this am
The red wire in my 3 pin connector shown in image 1 goes to the pressure switch in image 2.....
image 1

http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=IMG00164-20100610-2157-1.jpg
image 2

http://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=IMG00164-20100610-2157-1.jpg#!oZZ3QQcurrentZZhttp://s1252.photobucket.com/albums/hh568/duke9074/?action=view&current=acpressure.jpg


4) If you unplug the A/C pressure switch, does the A/C still work when you jump the wires? the answer is no the system turns off when the pressure switch is disconnected.

i believe i have provided all information requested if not please let me know sorry for the confusion and out of orderness i typed as i completed the tasks...

 

[duke9074]

edited

 

[RonJ]

Thanks^

At this point, it seems that the Blu/Wht wire for the pressure switch in the diagram is a Red wire in your car. The problem now is that we have no idea what your car's Blu/Wht wire is in the 3P connector. Therefore, we cannot interpret why jumping the two wires in the 3P connector makes the A/C run.

Therefore, to pinpoint the problem, we need to start fresh and do some basic tests that we can interpret.

Start by reconnecting all the loose plugs, and then do this:

Unplug the 2P connector for the pressure switch, start the engine, and then ground the red wire terminal in the 2P connector to the frame. Do the condenser/radiator fans run and does the compressor clutch engage? If not, try the same test but instead ground the blue wire.

 

[duke9074]

Correct on the the red wire I will run tests tonight after work if the rain stops. But for now I can tell u that the blue white wire in the 3p connector is battery voltage constant when key is in run position with nothing jumped or turned on.

 

[RonJ]

But for now I can tell u that the blue white wire in the 3p connector is battery voltage constant when key is in run position with nothing jumped or turned on.

It's possibly the Blu/Wht wire that supplies voltage from the blower relay to the blower motor.

My guess is that grounding the Red wire in the 2P pressure switch connector will make the A/C run, but I don't want to move to the next step until this is verified.

 

[duke9074]

Grounding both wires in the 2p pressure switch had no effect oh the system coming on. Tired this with both the a/c turned on and the a/c not turned on.

RON i can not follow this in a wire diagram but my hunch now is that the red wire in ac compressor 3 pin may be the power feed wire for the pressure switch, functioning as follows. The bluewhite wire in 3pin is constant hot my thought is that this may feed the red wire to the pressure switch thus the reason why the system turns on when these 2 are jumped and still turns off when pressure switch is disconnected. This would mean that the blue hot would travel down through the connector to the ac compressor be used on a switch passing back up through the connector and traveling to the pressure switch. I also believe the 3rd wire the blue with red line is nothing more then power to engage the clutch, which leaves me to believe the red and blue wire control the thermal switch. Is there a way to test the thermal switch. Tomorrow i will test continuity between the red and blue wire going down to the compressor in the 3 pin connector. Do you think this is possible? IF so why or why not? One catch to this theory is why does the ac switch on the heater control, control the system in reverse when jumped?

Note reading manual in your Sig stumbled upon a/c troubleshooting section 21-78......
i remember doing this on my own and will revisit it tomorrow more importantly is when i get to step 2 voltage here should be 12v i have 0v..... this can correct my theory above.. The blue wire is supposed to feed the 2p connector on pressure switch then flow to the red wire into the 3 pin and down to the thermal switch. Since im feeding the red wire when jumping this is powering the pressure switch and all components after it in the reverse flow causing the switch to be in the reversed phase. I am going to check the number 9 pin of the 12 pin connector f in under dash fuse box for voltage? And continuity from this wire to the blue pressure switch wire? Any possible fuse for this?

Yes i know i got a little ahead and carried away

 

[RonJ]

Grounding both wires in the 2p pressure switch had no effect oh the system coming on. Tired this with both the a/c turned on and the a/c not turned on.

This is clearly a problem.

my hunch now is that the red wire in ac compressor 3 pin may be the power feed wire for the pressure switch, functioning as follows. The bluewhite wire in 3pin is constant hot my thought is that this may feed the red wire to the pressure switch thus the reason why the system turns on when these 2 are jumped and still turns off when pressure switch is disconnected. This would mean that the blue hot would travel down through the connector tothe ac compressor be used on a switch passing back up through the connector and traveling to the pressure switch.

I can't rule out this rather convoluted idea, but this just isn't how Civic A/C circuits work. I can answer any questions you may have about how the circuit works.

I also believe the 3rd wire the blue with red line is nothing more then power to engage the clutch, which leaves me to believe the red and blue wire control the thermal switch. Is there a way to test the thermal switch. Tomorrow i will test continuity between the red and blue wire going down to the compressor in the 3 pin connector. Do you think this is possible? IF so why or why not? One catch to this theory is why does the ac switch on the heater control, control the system in reverse when jumped?

If the thermal protector switch were the problem, the compressor would not engage but the fans would still run when you did the 1-3 jump. I think this rules out a bad thermal protector switch.


Here's what I think you should try next, but first let me ask you a question. When you jumped the red to the Blu/Wht wire in the 3P connector, was the 3P connector unplugged or connected? I assume that it was connected. If so, plug all connectors back in, start the engine, and the use your jumper wire to ground the 12V Blu/Wht wire in the 3P connector rather than jump it to the red wire. Does the condenser fan run and the compressor clutch engage?

 

[RonJ]

Note reading manual in your Sig stumbled upon a/c troubleshooting section 21-78......

What manual?

 

[duke9074]

i have done it both connected and disconnected..... connected both the clutch engaged and fans ran disconnected just fans run..

i will try that test tomorrow with grounding the blue/white wire? Should i perform with a/c button selected or unselected? both? Blower speed? Do you have any other tests for me ? ANy hunch on what the problem is? Is this 3 pin connector not in any other civic?


where does the the blue/white wire that should turn system on when grounded in 2p pressure switch connector?



SITE 2

__________________
Don't guess, troubleshoot
-Manuals: site 1 and site 2; -Spark; -Fuses; -Pull 92-00 CEL codes; -Fuse 15 TSB; -Clean IACV or FITV

 

[duke9074]

where does the blue wire after the pressure switch go or come from ? What is the direction of flow there?
Also the one above? And last the blk yellow wire come from where and goes to where?

 

[RonJ]

i have done it both connected and disconnected..... connected both the clutch engaged and fans ran disconnected just fans run..

Interesting. I'll think more about this as it may shed light on where the wires in the connector go and do.

i will try that test tomorrow with grounding the blue/white wire? Should i perform with a/c button selected or unselected? both?

Off

Blower speed?

Off

Do you have any other tests for me ?

Not until we know the results of grounding the Blu/Wht wire.

ANy hunch on what the problem is?

The circuit goes like this:

12V from ECU --> Multiplex control unit (MCU) --> Pressure switch --> Heater control panel

The fact that grounding either wire in the pressure switch connector failed to activate the A/C fan and clutch tells you that the switch does not receive voltage from the MCU. This could be a bad wire or bad MCU (highlighted green).

Is this 3 pin connector not in any other civic?

I don't have a reason to believe that your A/C wiring is aftermarket.

where does the the blue/white wire that should turn system on when grounded in 2p pressure switch connector?

Not sure what you are asking here.

SITE 2

Which manual?

 

[duke9074]

edit it is site 1 civic 01-05 zip

MCU is the underdash relay and fuse box or is it a unit inside that unit?


Quote: where does the the blue/white wire that should turn system on when grounded in 2p pressure switch connector?

Not sure what you are asking here. Asking where the blue wire in the 2 pin connector goes to. Is it straight from MCU or does it pass through another location first?