Prevent A/C from engaging when using defrost?

[StillLearning]

I am ideally looking for an easy way to prevent the A/C compressor from enaging when using the defrost in my 07 Accord.

Over the summer noticed the A/C was very weak and starting to make a high pitched whining sound when turned on. I was told that was due to low refrigerant and that trying to use it when it was making that sound could potentially cause damage, so I just didnt use it. Now with winter upon us I would like to use the defrost without worry, but it seems to automatically engage the a/c.

 

[rijndael]

Unplug the AC Compressor Clutch Relay.

 

[97prizm]

I am ideally looking for an easy way to prevent the A/C compressor from enaging when using the defrost in my 07 Accord.

Over the summer noticed the A/C was very weak and starting to make a high pitched whining sound when turned on. I was told that was due to low refrigerant and that trying to use it when it was making that sound could potentially cause damage, so I just didnt use it. Now with winter upon us I would like to use the defrost without worry, but it seems to automatically engage the a/c.

Go get a refill kit that attaches to the low pressure side and refill your A/C. Do you have a leak?

 

[StillLearning]

Go get a refill kit that attaches to the low pressure side and refill your A/C. Do you have a leak?

I am assuming it must have a slow leak. Has been getting weaker over the years, jusy kind fell off a cliff over the summer.

To be honest, I did consider this, but everything I read said that there was high risk in using them and that it was not good to use one that had oil/stop leak, which every one I could find did. I will try taking another look to see if I can find one with good reviews and no additives.

 

[Chris142]

Unplug the AC Compressor Clutch Relay.

Or the compressor it's self or any pressure switch in the system.

 

[StillLearning]

Unplug the AC Compressor Clutch Relay.

That sounds like a solid option guaranteed to prevent to compressor from engaging.

Pardon my ignorance, but would this just a matter of unplugging a connection at the compressor itself?

 

[rijndael]

You could unplug it at the compressor, but then the connector ends will be exposed to the elements.

The fuse box is covered, so unplugging a relay is much less likely to get water/corrosion.

 

[CleanSump]

Fix the AC or hit the engine with a big hammer and duct tape it.

 

[meep]

You may find that the defrost is surprisingly ineffective without the AC. For some reason my old cars that didn’t have AC seemed to handle compressorless defrost far better than a new car that loses AC. The old cars had tons of ventilation - so the defrost could be on full heat and then floor ducts or side windows open to balance out the heat.

 

[Marcozi]

You can disconnect the connector on the compressor that supplies voltage to the electric clutch.

 

[Nukeman7]

You could unplug it at the compressor, but then the connector ends will be exposed to the elements.

The fuse box is covered, so unplugging a relay is much less likely to get water/corrosion.

^^^^This right here is the easiest and safest way to temporarily disable the A/C with no risk. The A/C relay in a 2007 Accord is shown in the photo below (where the needle-nose pliers are pointing).

 

[Maddy]

I am ideally looking for an easy way to prevent the A/C compressor from enaging when using the defrost in my 07 Accord.

Over the summer noticed the A/C was very weak and starting to make a high pitched whining sound when turned on. I was told that was due to low refrigerant and that trying to use it when it was making that sound could potentially cause damage, so I just didnt use it. Now with winter upon us I would like to use the defrost without worry, but it seems to automatically engage the a/c.

WARNING WARNING!!!!! You will need to check the A/C compressor and not try to disconnect it!!! It is not only used for cooling during the summer but also for the defroster!!

I thought my transmission was causing a horrible whine/groan, and my 2010 Honda CRV with 124K miles kept stalling out.
My CRV kept stalling out while I was driving, and I just turned off the engine, waited and then resumed driving. This Sunday it failed twice and twice on Monday on my way to work, so I dropped it off at my mechanic's shop. He drove it around and it stalled out for him and there was SMOKE under the hood. The A/C compressor was emitting smoke and was totally fried!!! I am picking it up today, after replacing the A/C compressor -- COST $1000 for parts and labor. This includes a transmission fluid change which I asked for, and getting new seals on my right axel, too.

The A/C compressor needs to be replaced. Don't risk a fire under your hood!!!

I posted my questions about the whine/groan on this website and stalling out and NO ONE indicated it could be the A/C compressor!!!! Everyone just said it's the engine or this or that.

 

[nascarnation]

Don't most modern A/C systems have a pressure switch that disables the compressor when the system is low on refrigerant? All my old GM beaters (MY 99/03/07) have this.

 

[Astro14]

WARNING WARNING!!!!! You will need to check the A/C compressor and not try to disconnect it!!! It is not only used for cooling during the summer but also for the defroster!!

I thought my transmission was causing a horrible whine/groan, and my 2010 Honda CRV with 124K miles kept stalling out.
My CRV kept stalling out while I was driving, and I just turned off the engine, waited and then resumed driving. This Sunday it failed twice and twice on Monday on my way to work, so I dropped it off at my mechanic's shop. He drove it around and it stalled out for him and there was SMOKE under the hood. The A/C compressor was emitting smoke and was totally fried!!! I am picking it up today, after replacing the A/C compressor -- COST $1000 for parts and labor. This includes a transmission fluid change which I asked for, and getting new seals on my right axel, too.

The A/C compressor needs to be replaced. Don't risk a fire under your hood!!!

I posted my questions about the whine/groan on this website and stalling out and NO ONE indicated it could be the A/C compressor!!!! Everyone just said it's the engine or this or that.

No one could answer your question because that question was based on a subjective description. You called it a groan - but I might have called it a screech - or a rumble. Either way, not enough information was provided for a reasonable guess at the cause.

Some of us did, in fact, tell you that it wasn’t your transmission, but you pressed ahead with that line of thinking anyway.

Your compressor seized. That adds up.

Your compressor wasn’t emitting the smoke by the way - that smoke was from your serpentine belt being dragged over a stationary compressor pulley on a seized compressor.

The OP already knows that the AC compressor is used for the defroster - and he can’t afford to fix it - that’s why he is asking about disconnecting it to enable him to use the defrost in the winter.

 

[CleanSump]

The OP already knows that the AC compressor is used for the defroster - and he can’t afford to fix it - that’s why he is asking about disconnecting it to enable him to use the defrost in the winter.

In that case, as others already suggested, unplug the clutch wire.

 

[ripcord]

The AC helps dry the air before it is heated by the heater core so your defroster will be less effective without AC, BTW

 

[Astro14]

The AC helps dry the air before it is heated by the heater core so your defroster will be less effective without AC, BTW

I believe the original poster has acknowledged that fact, certainly, you and I would just fix the thing, but I understand from his question that fixing it is not in his budget at the moment and he’s looking for a bridge to a future repair

 

[TiGeo]

A recharge can w/sealer is $45 at Walmart. Comes ready to go with a gauge. Just charge it so you can the drying benefits of ac when using defrost in the winter.

 

[Nukeman7]

Based solely on the description provided by the OP in Post #1, there are a couple of facts that need to be emphasized in this situation:

1. If the compressor clutch actually engages, the refrigerant may be lower than normal, but not low enough to cause the compressor to whine. The Accord's low pressure cutoff switch will de-energize the clutch engagement circuit when the low side suction pressure drops below approximately 23 psi of R-134a charge. Typically, the A/C system will not cool adequately and short cycle if the suction pressure is only slightly above the threshold (e.g., 25 psi), as it will fall below the cutoff value when suction is drawn with the compressor engaged. Topping off the refrigerant may actually increase the whining as the elevated pressure head will increase resistance within the compressor.

2. If the whining only occurs when the compressor is engaged, the bearing(s) in the compressor are worn/failing. If the whining is present when the A/C is turned off, the clutch pulley bearings are worn/failing. Per the OP's observations, it appears the compressor's internal bearing(s) are failing.

3. If the whining noise is only present with the clutch engaged, there is no additional risk in pulling the A/C clutch relay to allow heated air windshield defrosting for the winter season since the noise is emanating from the compressor's armature bearings, not the freewheeling clutch bearings.

 

[cb450sc]

I don't know if this applies to your Accord, but on my 05 Civic there is a procedure to do exactly as you are asking. I did it as soon as I got my Civic (used) in 2010. Check out some Accord sites to see if you can do it on your car