# AC issue, no cool air and refrigerant reads correct pressure



## thunderfrog (Jun 3, 2019)

Hi, My AC is not working in my 2010 rogue.. I hear the fan going but it doesn't blow cool air. I assumed that the refrigerant needed to be recharged, so I bought a can. The can has a meter which shows the current pressure in the system when you hook it up and the pressure registers in the normal range. So if the AC system currently has pressurized refrigerant, what is the next likely cause of the problem? Thanks


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## rogoman (Dec 16, 2004)

First, you need to eliminate the clutch on the A/C compressor as being the cause. Turn on your A/C and fans to the max setting. Is the clutch engaging? If not, use a voltmeter to determine if the clutch is seeing 12 volts.

If there's voltage, the clutch may be bad. Replacement of the clutch and/or compressor may be necessary. If there's no voltage, there may not be sufficient refrigerant in the system to engage the low pressure cut-off switch that cycles the compressor. If it seems likely that there isn’t enough refrigerant in the system, the typical culprit is a leak. Use an A/C leak detector to check for leaks, including in the condenser and evaporator. Next, use an A/C manifold gauge set to check the high and low side pressures in the system. Are they set within the recommended ranges provided in the FSM?

You can’t accurately diagnose your car’s AC by using the gauge on a recharge kit. The reason is you’re only seeing pressure on the suction or low side of the entire system. That’s not enough information to diagnose a problem. You can really screw up your car’s A/C if you overcharge or undercharge the system. Overcharging actually REDUCES cooling and undercharging can damage the compressor (refrigerant carries the lubricating oil so low refrigerant = oil starvation for the compressor).

So, if you really want to diagnose and fix your AC system yourself, you’ll need an AC manifold gauge set and hoses. Buy a set or rent a set, but don’t kid yourself into thinking you can make any kind of diagnosis without it.


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## smj999smj (Jan 1, 2006)

I've seen a number of A/C clutch field coils fail on 2005+ Nissans. If the clutch doesn't appear to be engaging, another thing you can try is an IPDM active test. It's a test that lets you check the circuit from the IPDM to several components, one of them being the A/C clutch, without even getting your hands dirty! Here's a YouTube vid that shows how to do it (it's not on a Rogue, but the procedure is the same):


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## cagailes281 (May 17, 2019)

I have an ‘01Frontier that after several hundred dollars spent on replacing parts determined that a sensor in the evaporator core ( a $25 part ) was not telling my compressor clutch to engage. It is difficult to replace this part because of its location.


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## smj999smj (Jan 1, 2006)

That part's called a "thermal amp" or "thermistor." It senses the temperature of the evaporator core and if it gets too cold, it will open the circuit to the clutch coil. It's to protect the compressor if the evaporator core should freeze up.


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## cagailes281 (May 17, 2019)

Yes! That was it! Cheap part but a real booger to replace.


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