Intermittant A/C failure when working hard

Tiny
TANIKIR
  • 2007 HONDA CRV
  • 92,000 MILES

When it is hot outside (90+) and the A/C is worked hard, it starts blowing hot air suddenly. This most often occurs when the max A/C button is selected but not always.

I have run the diagnostics by pressing the recirculate and rear defrost buttons, but no code is shown.

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Friday, June 29th, 2012 AT 4:27 AM

13 Replies

Tiny
WRENCHTECH
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They have been having a lot of problems with failed compressor relays on those recently.I would try swapping the relay with a like relay from something non-critical like the horn

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Friday, June 29th, 2012 AT 10:14 AM
Tiny
TANIKIR
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Which relay? I went do do this and found 3-4 relays that appeared to be A/C related and none for the horn.

Also, to complete the diagnostics I mentioned earlier is a code scanner needed? I was looking at the dash control panel for any codes to flash.

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Friday, June 29th, 2012 AT 7:40 PM
Tiny
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http://i1198.photobucket.com/albums/aa448/Wrenchtech/134771368.gif

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Friday, June 29th, 2012 AT 8:20 PM
Tiny
TANIKIR
  • MEMBER

I swapped the a/c compressor clutch relay with the rear window defogger relay and the a/c condenser fan relay with the fan control relay.

The problem appears to be resolved but I don't have the heat that caused previous failures. I will update later if this doesn't work.

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Friday, June 29th, 2012 AT 8:38 PM
Tiny
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You need to replace those relay/s with new ones now.

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Friday, June 29th, 2012 AT 8:43 PM
Tiny
TANIKIR
  • MEMBER

Relays weren't the problem. It started up again today. I tried checking the low side pressure, but the compressor wouldn't kick in so I know the reading isn't correct.

I bought a can of r-134a with a gauge to check the levels, but the gauge doesn't return to zero after being disconnected so I'm not sure if it can be trusted once the problem goes away so the compressor will kick in.

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Saturday, June 30th, 2012 AT 2:12 AM
Tiny
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You don't want to be arbitrarily dumping refrigerant in there. That system requires a very specific weight of refrigerant. If you put too much, you can destroy a $1,000 compressor and a lot more. That needs to be checked by a professional.

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Saturday, June 30th, 2012 AT 9:44 AM
Tiny
RFETESTED
  • MEMBER

I too am having this problem started about a month ago. Mine seems to work fine unless its run for a couple hours and you stop for gas or something then when you retstart the car the ac will only blow hot air for thirty minuites or so. If I leavfe it off for thirty minutes or so it usually (so far) starts blowing cool air again.

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Sunday, July 1st, 2012 AT 1:01 PM
Tiny
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Rfetested, you need to start a question of your own, not hijack someone else's

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Sunday, July 1st, 2012 AT 1:04 PM
Tiny
KHLOW2008
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Ensure the cooling coil is not frosted. That would occur when air leaks into cabin with thermostat set to minimum.

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Sunday, July 1st, 2012 AT 2:17 PM
Tiny
TANIKIR
  • MEMBER

Yesterday the compressor started working again and I could tell the true pressure. The gauge I was using has a high pressure when the compressor isn't on because it's also charged by the can that's connected. I found there was only around 10 lbs of refrigerant so I added a fair amount. When I ran out the system was around 30-35 pounds and only 5-10 lbs below the optimal charge for the temperature.

Even with the new refrigerant, the system ran for a minute and then the compressor started cycling on and off rapidly, spinning up and stopping once full speed was reached. I tried to see if driving would help as the engine speed seemed to be affected. After driving two miles I heard what sounded to be a long release of air, similar to a truck with air brakes. I shut the ac down until today.

Today the compressor ran fine for the first minute then started cycling again. I was able to ascertain the refrigerant pressure is at 25 lbs so apparently I didn't loose much yesterday.

I understand a mechanic will need to fix the leak, but I need to save every penny possible. Can I continue to diagnose the compressor? Is there a switch controlling the compressor that may have failed? I don't think there is time for the cooling coil to become frosted and it's not that hot today.

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Sunday, July 1st, 2012 AT 6:15 PM
Tiny
TANIKIR
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I'm wondering if the schrader valves need tightening. Could that cause the release?

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Sunday, July 1st, 2012 AT 6:17 PM
Tiny
KHLOW2008
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If pressure is going down, it means there is a leakage somewhere and you need to perform test to find out. Speculating is not going to solve the problem. If you keep putting in gas, it is going to cost you a lot of money for nothing. You would also be contributing to pullution of the atmosphere.

Without specialised equipment and proper diagnostics, you should not be attempting A/C repairs, especially if it involves depletion of freon.

For A/C diagnostics, you need to at least nkow the high and low pressure. Only one pressure reading is not going to tell you anything.

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Monday, July 2nd, 2012 AT 3:20 PM

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