2016 Suburban Ac Will Not Work. Temp Guage Reads 55 Degrees When It Is 85 Outside

Michael Thomas, automotive and diesel technician, is the author of the McGraw-Hill textbook "Truck and Trailer Systems."

Air-conditioning System Diagnosis

The typical complaint for an Air conditioning trouble is the AC blows warm air. This condition has a few possible causes: the Air-conditioning system could be low on refrigerant, an electrical problem may not be allowing the compressor to plough on, there could exist an internal problem in the system, or maybe in that location is a problem with the heater/AC controls. Since the most mutual problem is unremarkably the refrigerant, we will offset at that place.

Iii-Part Series

This series is divided into three parts. The AC arrangement operation, Air-conditioning arrangement service, and the diagnosis of a malfunctioning organisation. To be able to service and repair an Ac organisation, read through all three articles.

DIY Auto Service: Air Conditioning (Ac) System Operation with TXV or Orifice Tube

DIY Machine Service; Ac System Service and Component Replacement

DIY Car Service; AC System Diagnosis by Symptom

Static AC Estimate Pressures

Static Pressure means the organisation is not running. Compare this force per unit area with the ambience temperature to gauge the amount of refrigerant in the system. Less than the chart indicate low refrigerant charge and higher may indicated an overcharge.

Static Pressures

In that location is a human relationship between the pressure in the organization and temperature. A temperature pressure chart can be used to compare the pressure of the refrigerant at a given temperature. Since in that location is no way to know exactly how much refrigerant is in the system, without removing it and measuring information technology, we will use the pressure and compare it to a force per unit area temperature chart.

• Hook up a gauge set or recovery machine.
• Record the pressures. High and Depression Side should be equal.
• Measure the ambient temperature.

• Does the force per unit area friction match the temperature pressure chart?

  1. If the pressure matches this means the refrigerant level is close.
  2. If the pressure is lower than the nautical chart, the refrigerant level is low. The organisation is probably leaking.
  3. If the pressure is naught, that is atmospheric pressure and means the system has a big leak.
  4. If the force per unit area is college than the chart, it is either overcharged or may have air (not-condensable) in the organisation.

Leak Testers and Refrigerant Identifiers

If the Static Pressure is low, a leak is probably present. Use the leak tester for larger leaks and the Dye with a black calorie-free for smaller leaks. Place the refrigerant before hooking upwards to a recovery automobile.

Running System Pressures

Outset the engine and operate the Air conditioning system. Perform a visual check to see if the compressor is running.

1. Was a click heard when the AC was engaged? Is the centre hub turning?
2. Notice the pressure gauges. Does the low side pressure kickoff going downwards and the high side going upwardly?
3. After the system runs for awhile, raise the RPMs up to about ane,500 RPMs.
4. The organisation should be about 25 to 30 psi on the low side and 200 to 250 psi on the loftier side. If the ambient temperature is higher or lower than normal (70 to 80°F) the pressures will go upwards or downward accordingly.

Low and High Side Pressure the Aforementioned

No change in low side and high side pressures, the pressures are nevertheless equal.

• Double check to see if the compressor clutch is engaged. If the centre hub is turning, the compressor is not pumping.
• Shut the engine off and rotate the center hub past hand. Is at that place whatever resistance?

The compressor may be faulty.

Higher Force per unit area on the Gauges

Higher Force per unit area on both the High and Low side may indicate an overcharge or lack of cooling at the Condenser.

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Higher-Than-Normal Pressures

Higher than normal pressures on both high and depression side with the correct corporeality of refrigerant, could hateful a problem with air catamenia thru the condenser.

• Is the condenser or cooling fan working?
• Does the condenser have bent or dirty fins?
• Is there blockage inside the condenser?

Lower High and Low Pressures

Lower pressures may point low refrigerant level or a weak compressor.

Lower Low and Loftier Side Pressures

Lower than normal pressures on both high and low side, with the correct amount of refrigerant, could mean a problem edifice pressure in the system or too much heat is being removed at the condenser. Is the ambient temperature low?

With the system running place a fender cover in front of the condenser and discover the pressure.

• Does the pressure level go up? Can the compressor build the pressure? If not the compressor may exist worn out.
• Is the cooling fan running constantly? A pressure switch or sensor could be bad.

Lower Low Side and College Loftier Side Pressures

This condition usually ways there is a restriction in the system or the TXV/Orifice Tube is blocked or closed. Experience the lines, is there a pressure/temperature drop at the TXV/Orifice Tube?

• With a drop, there may be a restriction at the TXV or Orifice Tube.
• With no drop, in that location may be a restriction upstream from the TXV or Orifice Tube. Follow the liquid line back towards the condenser to meet if you lot can experience a pressure/temperature driblet.

Higher Low Side and Lower High Side Pressures

Also much refrigerant is flowing into the evaporator.

• The TXV is stuck open up or the thermal bulb is not sensing the temperature correctly.
• The orifice tube is as well big of an opening or the o-ring sealing the outside of the orifice tube is not sealing.

System Pressures Are Normal, merely Warm Air Is Blowing Out of Vents

Some times the refrigerant part of the system is not where the problem lies. The AC and Heater operate out of the same box or plenum typically nether the dash. Doors control the management of the airflow created past the electric blower motor. Depending on the system, at that place are at least 3 to four doors controlled by cables, vacuum actuators or electronic motors.

These doors are:

• Hot/Cold temperature door - controls the amount of airflow through the heater core. During AC (Cold) functioning, this door may forcefulness the air to featherbed the heater core. When the temperature lever is prepare to Hot, all the air is forced through the heater cadre to use the heat from the engine coolant to rut the cab.
• Fresh Air/Recirculate door - This door selects whether the air is drawn from the outside or circulate the air within the vehicle. Recirculating the libation drier air within the passenger compartment can assistance maintain a cooler temperature instead of cooling the hot moist outside air. Typically some outside air is e'er added to keep the passenger compartment pressurized to prevent exhaust from inbound the passenger compartment.
• Floor/Vent/Defrost door or doors - This door or a combination of doors controls where the cooled or heated air is sent. Floor mode typically for heater operation since rut rises. Vent out the center of the dash for Ac performance. Summit of the dash to defrost the windshield during common cold atmospheric condition. At that place may likewise be combinations of floor/vent or flooring/defrost to adapt dissimilar situations.

AC Heater Plenum

The AC Heater box or plenum is located under the nuance. Electronic actuators with position sensors are very popular to movement the doors to direct the airflow and control temperature.

With or Without Hot Water Valve Systems

In that location are ii basic designs for the airflow:

1. All the airflow goes thru both the evaporator then the heater core. A hot h2o valve closes the flow of hot coolant thru the heater core during the AC performance. If this valve doesn't close, the AC cold air will be heated past the heater core. If the valve sticks airtight, in that location will exist no heat. The result is hot air out the vents. In the defrost manner, the air will be dehydrated by the evaporator then heated by the heater core for hot dry out air on the windshield.
2. The airflow goes thru the evaporator and a door directs the air either thru the heater cadre or around the heater core directed past the HOT to Common cold selector. During Air conditioning Common cold operation, the "Blend Door" routes the cold air effectually the heater core. During Heat operation, all the air passes thru the Evaporator and the Heater Core. When the temperature is set in between, part of the air will pass thru the Heater Core. No hot h2o valve is needed considering in cool fashion the door closes off airflow thru the heater cadre.

When the Air passes thru the evaporator and heater cadre as in example ane above, a hot h2o valve is used to shut off the HOT h2o to the heater core. These Hot Water Valves can be; Cable operated, Air Operated and Electric Solenoid operated.

Door Controls and Actuators

To control the airflow thru the heater box or plenum a series of doors are used. To command these doors a multifariousness of actuators take been used such as:

• Manual cable operated doors have been around a long fourth dimension. Cables connect levers in the dash control to the doors. When a lever is moved back and forth, like the hot/cold lever, it moves the door from one position to another. Typically moving the lever rapidly from i farthermost to the other results in a thumping sound equally the door hits the stops. The Hot/Cold door would control airflow around or thru the heater command. Cables popping off or improper adjustments are typically what will become wrong with this style of control.
• Vacuum operated actuators, used on cars and light duty trucks use (gas) engine vacuum to act upon a diaphragm which is continued to the doors. As the controls are moved, a hissing audio is heard. Vacuum leaks are the biggest problem with this type of control. If the vacuum supply is disconnected, the controls usually default to putting air on the windshield. Diesel engine light trucks using vacuum controlled systems utilise an electric or belt driven vacuum pump to supply the vacuum.
• Pneumatic actuators operate like to the vacuum type, except the trucks air system force per unit area is used to move the actuator diaphragms. Hissing nether the dash could be from a leaking actuator or connection.
• Electronic actuators utilise an electric motor to position the doors. These electrical motors usually take a sensor congenital in to allow the system to know the location of the doors. When the controls are moved, a small electric motor buzz tin can usually be heard.

Service Tip: A common trouble with all the actuator types are paper clips, pens, keys and other strange objects falling down into the heater box from the dash defroster vents and jamming the doors. This could also strip out the door connection to the actuator rod.

Cabin Filter

Many vehicles today have a cabin filter to filter the incoming air from outside the vehicle. The filter looks like a small air filter from a motorcar. Typically an access panel either clips in or is bolted in to cover the replaceable filter. The filter may be located under the dash or on the heater box in the engine compartment. This filter is oftentimes disregarded until information technology is entirely plugged upward and causes very niggling airflow into the cab.

If the cabin filter is dirty the effect will be low airflow. This may cause the AC or heater output to be reduced. Many times this is dislocated with poor Air conditioning or Heater functioning due to the fact that the depression airflow cannot go along the vehicle cool/warm.

Dirty Evaporator

The dirt on this evaporator has restricted the airflow and caused a lack of cooling.

Dirty Evaporator

The airflow across the evaporator is used for cooling the air. If clay, fuzz, leaves or plastic bags are covering the surface, the airflow will be reduced along with the cooling capacity. The Ac system may exist in good working order only the air cannot have the heat removed as information technology should. The complaint will be lack of cooling the aforementioned condition as a plugged motel filter.

This article is accurate and true to the all-time of the author'south cognition. Content is for advisory or entertainment purposes only and does non substitute for personal counsel or professional communication in concern, financial, legal, or technical matters.

Questions & Answers

Question: How near if the static pressure is not equal. 50 psi on low pressure and 180 psi on high pressure level with an outside of temperature of 75F, what does this mean for diagnostics of an AC system?

Answer: With the organisation not running the pressure should equalize thru the Orifice Tube or H-cake. When y'all shut off the AC you hear a hissing noise. I would say in that location is something wrong with the gauges. What happens when the organization runs, do the gauges both move?

Question: How practice you tell if the condenser is restricted ?

Answer: Past the temperature in and out. Hot in, common cold out is restricted. Usually, the high side is really high and depression side really low.

Question: I have a 2008 Rav4. Twice I have tried to accuse the A.C. organisation to the proper pressure. When the proper pressure is reached, the vents accident warm air and the compressor drops out. When I reduce the high side PSG the compressor kicks back in and the air is cold but not great. Could it be the hullo pressure level switch?

Answer: 1st we don't accuse to a pressure, the organization is filled to the proper chapters in pounds or kilograms. The system must be evacuated before charging.

Question: I have a 1998 Monaco motorhome. I evacuated the organisation to get ready to add 134a. It would non take whatsoever and I have the compressor clutch engaged with a hot wire. Both gauges are reading zippo. I'chiliad thinking a bad compressor could this be right or something else?

Reply: Sounds similar the gauges are not connecting. This is the reason you can't add refrigerant.

Question: When I try to connect the coupler to the depression side, it gives me a reading of 80-100 psi and it doesn't stay secure. What makes the coupler not to stay secure?

Respond: Wrong or damaged coupler would be my approximate.

Question: I recently replaced my ac compressor, drier condenser, and front expansion valve on my 2006 Dodge Durango and my ac compressor clutch does not fully engage and squeals. What should be my next pace? 2006 dodge Durango slt 4.7l with front and rear air conditioning.

Answer: 3 things to bank check

one. Clutch plate air gap between the plate and the caster in specs.

2. Voltage at the compressor, should be 12V

3.Voltage drops in + or - side of the Air-conditioning circuit, bad connections or corrosion (in the lesser of fuse panel) causing voltage drops.

Question: During a pressure level examination, the low side is at 54 and the high side went to 150 and then dropped to 80psi?

Answer: Since I don't know what organisation yous have, I have to guess. Sounds like either a bad compressor or a bad H-block.

Question: 2020 mustang air works when it wants to. High side reading is normal but low side immediately pegged the gauge and didn't move. Didn't read anything on here well-nigh normal high side but high depression side. What's probable the culprit?

Answer: 2020 Mustang should be R1234yf refrigerant. Low side pressure is controlled by the H-cake.

Question: When my automobile is running, the low side reading fluctuates at around 50PSI and sometimes to negative pressure. High side reading stays stagnant at 100PSI. Not-and so-cool air is beingness blown out. Ambient temperature thirty degC. What could be the problem?

Answer: Not enough data. But the loftier side is extremely low. If the system is properly charged it seems the compressor is not working up to par.

Question: I have a 1998 suburban with rear a/c. The pressures are 30psi on the low side and 165psi high side. It cools to virtually 45 in the front end and threescore in the rear. The compressor clutch stays engaged and the pressure readings stay the same. It has a new compressor, orifice tube, and accumulator. It had this trouble prior to replacing these parts. I pulled a vacuum on the organization prior to charging. Any thoughts?

Respond: Usually, the problem is reversed. The rear air-conditioning uses a TXV/H-Block and it sounds like the valve is not working. The systems with rear ac hold more than refrigerant, usually near 3.eight pounds. Should exist a tag on the radiator support.

Question: I charged the A/C system. The air inside cab is down to 50 degrees. Depression side of Estimate reading is 40-fifty psi. High side of gauge reading zero, but the cab is absurd. I collection around for about an hour with the outside temperature 88 degrees. What is up with the high side?

Respond: The organization tin can't be zero on the high side. There must exist a connection trouble with the high side coupler. The organisation should cool downward to forty degrees.

Question: I can't plow off my a/c. When it'due south switched on it works slap-up. When I switch information technology off information technology still blows semi cool air. The switch is functioning correctly. Could the compressor clutch exist partially sticking? The automobile is a 2006 Hyundai Accent.

Answer: If the clutch has power to it after close off, the Air-conditioning relay may be stuck on.

Question: What is wrong when your a/c is in retard department of low side judge?

Answer: This means your low side pressure is in a higher place 150psi. System must exist overcharged or your gauges are somehow continued incorrect.

Question: My automobile reads 30psi low side at idle and loftier side reads 70-75 psi...no cooling effect...static pressure is 50psi... Ambient temperature is xxx.c... Is my AC is undercharged?

Respond: Sounds undercharged. Leak?

Question: What causes the hig side pressure to exist low? I accept a 1955 Ford with a vintage A/C and the air is cold only when I check the A/C pressure it is xxx/110 and the exterior temperature about 85 degrees. Is that normal?

Reply: I presume information technology is an R12 system that has been converted to R134a. The lower loftier side pressure may exist from an undercharged system and the TXV is keeping the low side at 30 PSI. The old systems used a sight glass to charge the systems. Detect the sight glass and observe the refrigerant flow while the system is running. If the sight drinking glass is articulate liquid the system is fully charged. If information technology looks foamy or has bubbling the system is undercharged or contaminated with air. Since information technology does absurd I would remember it is close to beingness charged.

Question: Motorcar has front and rear Ac, the front but blows cold if the rear is on?

Answer: Does the compressor kick on with the forepart ac on only? If not front end ac command problem.

Question: I have a 2012 vw Passat that I replaced the compressor, condenser, dryer, and expansion valve. Charged up to right refrigerant specs of 575g. When I turn ac on it will blow cool air for a minute and then both high side and depression side pressures drop to about zippo and compressor will blow out refrigerant from the pressure relief? Any suggestions?

Answer: Never seen this before. Sounds like a blockage in the high side line to compressor discharge oort.

Question: I take a 2010 Nissan Altima that I modify the compressor,expansion valve, condenser and switch. I vacuumed the system and put new refrigerant. Information technology works merely, the adjacent day doesn't piece of work. I did this ii times and pressure is the on the low and high?

Answer: Sounds like yous accept a leak. Without knowing static pressure this is a gauge.

Question: I have a 1996 Dodge Ram Diesel. Low pressure was normal, simply the loftier pressure was extremely high. Why would my Dodge's AC pressures be so different?

Answer: Sounds like poor airflow across the condenser. Cooling fan problem, plugged or blocked condenser are the probable causes.

Question: The A/C compressor has seized on my 2000 Sienna. I take to bypass with the belt. My mechanic says any bypass belt still will apply the caster or pass through the area of the compressor caster. Does that make sense? Why would they call it a bypass belt if that is the case?

Answer: If the compressor seized, the pulley should however turn. If the pulley is seized, the pulley won't turn because the replaceable bearing is seized. Usually, to use a chugalug without air conditioning, you need to remove the compressor as if it didn't have ac.

Question: Why does the air conditioning cut off every time I brand a plow?

Answer: The computer senses the extra load added by the power steering and turns off the ac until the load is reduced. Typically used on pocket-sized engines.

Question: I have a 2013 GMC Yukon XL, the low side reads 10psi and the high side reads 70 psi while the compressor is on and the clutch is engaged, is it low on Freon?

Reply: Sounds similar information technology. Accuse with DYE and retest with a black calorie-free.

2016 Suburban Ac Will Not Work. Temp Guage Reads 55 Degrees When It Is 85 Outside

Source: https://axleaddict.com/auto-repair/DIY-Auto-Service-AC-System-Diagnosis-by-Symptom

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