2006 civic A/C Continuous cycling on and off.
09-21-2014
#1
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2006 civic A/C Continuous cycling on and off.
The A/C clutch engages for 30 seconds then releases for 30.
I have checked the pressure and added Freon to top off it really did not need it
as it was just a bump added to see if it was the low pressure switch and this still did not affect it.
changed relay for compressor with no help. while checking web for ways to jump switch I found no correct way to jump the 3 wire connector just that if you power the green to pcm it will fry it, so I left that alone.
I do have a good mechanical background and unlike older units with two wire it is easy.
anyway the clutch and compressor seem fine after probing the connector on top of the alternator there are three wires and the center one powers the clutch and it sees 14 volts and the outside two show 0v when A/C is on and both rad fans are running.
then after a short time the fans and the clutch disengage and there is no current to the compressor and now the two outside wires have 14 volts.
and when it is hot outside it runs great for 5 min then stop working.
so here is what I have
1 freon fine
2 relay for compressor changed
3 clutch engages fine
4 fans cycle with clutch engagement
any help welcomed
Thanks
I have checked the pressure and added Freon to top off it really did not need it
as it was just a bump added to see if it was the low pressure switch and this still did not affect it.
changed relay for compressor with no help. while checking web for ways to jump switch I found no correct way to jump the 3 wire connector just that if you power the green to pcm it will fry it, so I left that alone.
I do have a good mechanical background and unlike older units with two wire it is easy.
anyway the clutch and compressor seem fine after probing the connector on top of the alternator there are three wires and the center one powers the clutch and it sees 14 volts and the outside two show 0v when A/C is on and both rad fans are running.
then after a short time the fans and the clutch disengage and there is no current to the compressor and now the two outside wires have 14 volts.
and when it is hot outside it runs great for 5 min then stop working.
so here is what I have
1 freon fine
2 relay for compressor changed
3 clutch engages fine
4 fans cycle with clutch engagement
any help welcomed
Thanks
09-21-2014
#2
If you think a good mechanic is expensive, try hiring a bad one
Re: 2006 civic A/C Continuous cycling on and off.
A very capable scanner datalist can show you the
AC request signal (ON/OFF)
AC compressor clutch command (ON/OFF)
High side AC pressure sensor value (PSI)
ECT value (degrees)
and more....
All from the comfort of the drivers seat.
A pressure gauge set should be used to check and verify the AC pressure sensor is reading accurately, and you should verify the high side pressure is not excessive when the system cuts off.
It cuts off at around 450 PSI (IIRC). If it's running that high, it's overcharged.
What is the voltage on those two wires when the AC system is turned OFF at the control panel?
A wiring diagram would tell you which control units are involved in the operation of the AC system (HVAC control head, MICU, PCM?), along with showing how the thermal protector is wired in to the system.
Sorry, no silver bullet here. You'll have to do your own legwork.
AC request signal (ON/OFF)
AC compressor clutch command (ON/OFF)
High side AC pressure sensor value (PSI)
ECT value (degrees)
and more....
All from the comfort of the drivers seat.
A pressure gauge set should be used to check and verify the AC pressure sensor is reading accurately, and you should verify the high side pressure is not excessive when the system cuts off.
It cuts off at around 450 PSI (IIRC). If it's running that high, it's overcharged.
and now the two outside wires have 14 volts.
A wiring diagram would tell you which control units are involved in the operation of the AC system (HVAC control head, MICU, PCM?), along with showing how the thermal protector is wired in to the system.
Sorry, no silver bullet here. You'll have to do your own legwork.
09-21-2014
#3
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thanks much.
It was cycling like this before any freon was added and has never been charged before this from factory.
the voltage I checked was from the plug off the compressor and it was 14 volts
from both.
I swapped relays and still the same.
I can only think it is a sensor either from the heat relay on the compressor or a defective low pressure switch.
Thanks Marty.
there is no voltage while the compressor is engaged and when it cycles they get the voltage and the compressor
has none.
with the controls off there is no voltage in any of them.
It was cycling like this before any freon was added and has never been charged before this from factory.
the voltage I checked was from the plug off the compressor and it was 14 volts
from both.
I swapped relays and still the same.
I can only think it is a sensor either from the heat relay on the compressor or a defective low pressure switch.
Thanks Marty.
there is no voltage while the compressor is engaged and when it cycles they get the voltage and the compressor
has none.
with the controls off there is no voltage in any of them.
Last edited by kart kid; 09-21-2014 at 05:57 PM. Reason: more info.
09-21-2014
#4
If you think a good mechanic is expensive, try hiring a bad one
Re: 2006 civic A/C Continuous cycling on and off.
I can only think it is a sensor either from the heat relay on the compressor or a defective low pressure switch.
There is no low pressure switch, there is only one pressure sensor that reports directly to the PCM.
Quote:
<table border="0" width="100%" cellpadding="6" cellspacing="0"> <tbody><tr> <td class="alt2" style="border:1px inset"> and now the two outside wires have 14 volts. </td> </tr> </tbody></table>
What is the voltage on those two wires when the AC system is turned OFF at the control panel?
Damn.
09-21-2014
#5
If you think a good mechanic is expensive, try hiring a bad one
09-21-2014
#6
If you think a good mechanic is expensive, try hiring a bad one
Re: 2006 civic A/C Continuous cycling on and off.
there is no voltage while the compressor is engaged and when it cycles they get the voltage and the compressor
has none.
with the controls off there is no voltage in any of them. <hr style="color:#CEE6EE; background-color:#CEE6EE" size="1"> Last edited by kart kid; 4 Minutes Ago at 05:57 PM. Reason: more info.
has none.
with the controls off there is no voltage in any of them. <hr style="color:#CEE6EE; background-color:#CEE6EE" size="1"> Last edited by kart kid; 4 Minutes Ago at 05:57 PM. Reason: more info.
09-21-2014
#8
If you think a good mechanic is expensive, try hiring a bad one
Re: 2006 civic A/C Continuous cycling on and off.
Sounds like the system may be cycling off then.
(This is where I really need to know what the computer is doing: AC request signal status tells me a lot.)
Without knowing that, I guess my next wild stab might be checking the request signal (pinout voltage testing) on the HVAC controller wiring to see if that is what is actually controlling the system on and off.
Maybe checking the resistance of the evap temp sensor, maybe it's reporting the temp too low. (10K ohms @ 75 deg F)
(This is where I really need to know what the computer is doing: AC request signal status tells me a lot.)
Without knowing that, I guess my next wild stab might be checking the request signal (pinout voltage testing) on the HVAC controller wiring to see if that is what is actually controlling the system on and off.
Maybe checking the resistance of the evap temp sensor, maybe it's reporting the temp too low. (10K ohms @ 75 deg F)
09-21-2014
#9
If you think a good mechanic is expensive, try hiring a bad one
Re: 2006 civic A/C Continuous cycling on and off.
Without knowing that, I guess my next wild stab might be checking the request signal (pinout voltage testing) on the HVAC controller wiring to see if that is what is actually controlling the system on and off.
Pull the HVAC control panel out and try swapping one in that you know works right. Know anyone with an identical car?
09-21-2014
#10
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No I do not.
I will try to find a way to get the info and search from there.
There is a low pressure switch but not sure how to jump it. It is a three wire one.
I will try to find a way to get the info and search from there.
There is a low pressure switch but not sure how to jump it. It is a three wire one.
09-21-2014
#11
If you think a good mechanic is expensive, try hiring a bad one
Re: 2006 civic A/C Continuous cycling on and off.
This is another reason why a very good scanner is needed.
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