Redundant AC Not Blowing Chilled Air

Current Mileage- 108,000 miles
Vehicle has never had refrigerant added to system.
Belt is good and ac clutch spins freely by hand but will not engage when engine is operating at normal temperature and ac is on and set to lowest temp setting. Is it possible I can start adding refrigerant and the compressor clutch will engage allowing me to add additional refrigerant to within normal specified pressure range?

If you are asking here then I think it best to have an actual air conditioner shop solve the problem .


To answer your question, yes, it is possible your system is low. but without the proper gauges and knowledge you can do more harm. I suggest you follow the above advise.


Did you let the pump cycle on and off from low refrigerant to the point where the clutch wore out?

If the clutch plate turns without resistance, the system might be empty.
Inspect the condenser for stone damage,

With all due respect I was under the impression that this forum was a place for members to discuss mechanical issues and offer repair information he or she might have from encountering the same issue. Perhaps I have misinterpreted the intent of the forum.

1 Like

You have the right impression but not knowing your mechanlcal knowledge they are giving you good advice.


AC is generally not a DIY service. If the system is low, you have a leak. Just adding refrigerant from one of the recharge cans can result in injury to you and/or damage to your AC system.

AC service takes proper tools and training. That is why we say take it to a pro.


The one thing you can check that you did not say if you did or did not check, are the fuse and relay for the A/C. That should be the first thing to check before going to the shop.


First step with an inoperative A/C system is connect the gauge set and see what the static pressure is. Meaning the high and low sides are equal with both engine/A/C off. The norm is around 120 PSI or so.

If the system is not engaging because of a low refrigerant level then you have to assume it’s low because of a leak; or plural of that.
As mentioned, DIY A/C repairs can be hazardous in spite of the TV commercials making it appear to be so easy.

1 Like

Static pressure in an A/C system is directly related to the ambient temperature…


I respectfully disagree with those charts. It’s often brutally hot here in OK. I have never seen any vehicle no matter the make or model (including new/near new warranty issues) with a static pressure higher than 125 PSI or operating high side pressures with elevated RPMs higher than 250 or so.

The norm here is 120 static and high side pressures run about 225 on average even when the ambient temps are 100 to 105.
Last Saturday was 110 even but we have several days of cooler weather before the well over a 100 garbage starts again first of the week.

And that is what that chart says.

At 100 it’s 4+ PSI. Even on 108 degree days I’ve never seen one over 120 except in an overcharge situation. Shows 110 PSI the charge is down a bit. Shows a 100 or less the charge is significantly down.

Note at 108 degrees the chart shows 142 and at 110 shows 146. With static pressures like that the high side is going to be too high and that also drives the low side up. Again, even on 110 days I’ve never seen a system in excess of 120 other than an overcharge.
And I’ve also never seen much of a difference in static pressures when comparing a 99 degree day to a 108 degree day. Just my personal experience is all.

We also try to warn people of things that can be dangerous (or cause damage) if done improperly. Most of us here don’t recommend doing A/C work yourself unless you know what you’re doing.


And even if you know what you’re doing, some folks take it to a good shop. I do, I installed an a/c system on one of my cars, I worked on a/c systems at the garage, I have a set of gauges gathering dust in my tool box. I always take it to a shop now.


I’m still wondering why a Hyundai Elantra has or would need a “redundant AC” system. It’s not like it mission critical.

I agree with texases, over ther years I’ve done pretty much everything that can be done on a car but A/C is the one area I won’t touch.
Even if you have all the necessary tools, don’t injure yourself or do more damage, a good mechanic can often do the correct repair better and cheaper than you can DIY.

1 Like

Since redundant is usually defined as something that is superfluous, or not necessary, or no longer needed, I’m assuming that the OP lives in an area that never experiences hot weather. If I lived in an area like that, I wouldn’t be worried enough about the functioning of the A/C to spend any money on repairing it.

Perhaps the driver works at the Department of Redundancy Department?