How to troubleshoot av acuum leak at the fan air conditioning panel

First thing you should check are the fuses. Usually on domestic vehicles, you'll find the main fuse panel under the hood, check your owners manual. Second, all air conditioning compressors require a certain level of freon within the system to operate. At most auto parts stores, they sell freon in a can. I've used it once and it seemed to work effectively. The nagging question is, "where did the freon, that was in the system, go"? Some of the freon purchased from the Parts Stores have a dye in it that can be seen with the use of a "black light". The purpose of the dye is to determine when and where a leak is. I have a Yukon that has a slow leak that I have never been able to locate. Once I charge it, compressor function and cooling will last for one summer season. Good luck.

sounds like an air conditioning issue if your only complaint is the fans not coming on when air conditioning is used. you need to have the a/c sys checked out to see if you have a leak or perhaps refrigerant may be low. sometimes you may have a compressor that no longer works so the system may not be building up pressure so the pressure switch does not cycle the fans.

Since the failure of an air conditioner to turn on, loss of air conditioner cooling capacity, reduced air conditioning output temperatures, loss of cool air supply, or even loss of air flow entirely can be due to a variety of problems with one or more components of an air conditioner or air conditioning system, after reviewing the lost air conditioner cooling diagnosis procedures described in this article, be sure to also review the diagnostic procedures at each of the individual air conditioning diagnosis and repair major topics listed just below. To return to our air conditioning and refrigeration home page go to AIR CONDITIONING & HEAT PUMP SYSTEMS.

Electrical problems on HVAC systems: Keep in mind that despite the depth of technical detail you will find here about all components of air conditioners and heat pumps, most service calls for non-working air conditioners or heat pumps turn up an electrical problem. So if your A/C system is just not working at all be sure to check all of our electrical and control setting suggestions first.

Mechanical problems on HVAC systems: tend to fall into these groups: refrigerant leaks, dirty condenser coil or unit, dirty evaporator or cooling coil, or burned out (or hard-starting) compressor motors. We have also seen a number of problems with fans and fan motors in both the compressor/condenser unit and in the air handler/blower fan unit. Some of those fan problems are mechanical - like a loose fan belt or blade. MORE DETAILS

The first thing to do is see if the indoor (evaporator-air handler) fan and compressor are both running at the same time, then turn the unit off and let all the ice melt.
If the compressor is running and the evaporator fan isn't, you've already found the main cause of your air conditioning freezing problem.
The indoor coil will freeze up if the compressor runs without the evaporator fan running.
Check to see if ice has built up enough to stop the fan.
If it has, (and it's possible with wall mounted ductless mini split units and some window units), the fan may run normally once the ice melts, and the cause of your air conditioning freezing problem could be something else.
If you are the equipment owner trying to take care of this air conditioning freezing problem yourself, and you get to the point that you have to call in a technician, it could save him time, (which saves you money) if you have already verified whether the evaporator fan was or wasn't running with the compressor, and if ice had built up enough to stop the fan.
Once the ice has melted, check the fan or blower blades, and see if they're clean and not obstructed by something like a plastic bag, other debris, or mould growth.
Remove any obstructions, and if necessary, remove the blower and clean it.
Before tearing into the rest of the unit, check the thermostat and make sure it's working right.
Do the cool contacts open when the t-stat is turned up to a higher temp than the room temp?
If not, the thermostat has failed, and never turns the unit off, which can definitely cause an air conditioning freezing problem.
Do the fan contacts open and close when the thermostat setting is turned higher and lower than the room temperature?
If the fan contacts never close but the cool contacts do, the thermostat has failed and caused your air conditioning freezing problem.
If the fan contacts close, but the fan doesn't run, check the fan relay in the air handler.
If the fan relay is not getting control voltage, the circuit is open between the thermostat and the fan relay.
Look for a loose connection, wrong connection, dis-connection, or broken wire.
If it gets control voltage but doesn't energize, it has failed, and must be replaced.
If it energizes but the fan doesn't run, check for line voltage on the load side of the relay.
If there is line voltage on the load side of the relay and the fan doesn't run, you'll have to troubleshoot the load side circuit and the fan motor as detailed further on.
If the thermostat checks out ok, set the thermostat to "fan on" and make sure the blower runs in the correct direction and at the proper RPM, that it is installed in the housing correctly, and is the right size.
If the blower is installed backwards or is running in reverse, the coil can freeze up. (Although I have seen several units that didn't freeze up with reversed blowers.)
You will need to turn the blower around, reverse the rotation of the motor if it is a reversible rotation motor, or install a motor with the correct rotation.
A blower that runs too slow can cause an air conditioning freezing problem.
You'll need to install a motor that runs at the correct speed.
A blower that is too small, or that is installed in the housing incorrectly, can cause an air conditioning freezing problem.
You will need to install the correct size blower, and be sure it is installed correctly in the housing.
This means centered, with volutes installed, and the curve of the vanes matching the outlet of the housing.
If the blower motor is the wrong size, if the bearings are failing, or if it has an open start winding or a failed run capacitor, it could be overheating and stopping intermittently.
A motor that is overheating and stopping intermittently can cause an air conditioning freezing problem.
To check out the evaporator fan motor:
Check the resistance readings of the motor windings.
If you get a readable resistance between all three windings, the motor windings should be ok.
Turn the shaft. If it turns free and easy, the bearings should be ok.
If the shaft is hard to turn, lube the bearings with 20 SAE electric motor oil if there are lube ports.
If that frees the shaft, it should run ok for a while, but the bearings or bushings may be deteriorated to the point that they'll sieze again soon.
If the shaft doesn't free up, replace the motor.
If the shaft turns freely, check the capacitor.
The best way to check the capacitor is to replace it with a new one of the correct rating.
If the motor runs, close the air handler panels, and take an amp draw on the motor.
If it's normal it should run OK, and if the motor was the problem, your air conditioning freezing problem should stop.
Ok, if you've verified that the controls and fan are good, take a break for a diet soda, and then we'll see if the evaporator coil or ducting are the cause of your air conditioning freezing problem.
Take a look at the evaporator coil.
Is it clean? Can you see your flashlight shining through from the other side?
If the coil's dirty, you'll have to do some air conditioning coil cleaning.
If your air conditioner is a window type, our page about how to clean window air conditioners has some pointers you might find useful.
A dirty evaporator coil is a common cause of air conditioning freezing,
And it's one of the problems that can be prevented with regularly scheduled air conditioning maintenance.
If the coil is clean, check the ducting to make sure nothing is blocking air flow.
Blocked ducting will stop air flow through the evaporator coil, and this will cause the coil to freeze up.
If your coil is clean and the ducting is clear, let's run the unit and check the operating pressures and temperatures.
If your discharge and suction pressures are low, with a low compressor amp draw, low subcooling, high superheat, and low temperature splits accross your evaporator and condenser coils, you probably have a leak.
Shut the unit down, find the leak and repair it.
Once the leak is found and/or repaired and you're ready to run the unit, our Charging Air Conditioning Systems page offers some tips that you might find helpful.
If you are totally unable to locate the leak with a bubble solution or electronic detector, you'll have to charge in refrigerant to correct pressures, temperatures, and superheat and subcooling values, and it would be a good idea to add some air conditioning leak detector dye so the leak can be found later on.
You have to use some common sense about leaks.
If the leak is so small that you can't find oil or any other sign; unless the customer agrees to pay you for all the time you spend, it's more cost effective to charge in the small amount of refrigerant it will take to get the unit running correctly, finish the service call, and be on your way.
I can't imagine that there's a service technician out there who hasn't run into the same problem many times.
Use some common sense, be up front with your customer, and if you've done your best not only to find the leak, but to get the unit running right and save your customer unnecessary expense, consider it a job well done.
If your suction pressure is low enough to cause the evaporator to freeze up, but you have high subooling and high superheat, either your metering device is restricted or the wrong size, your drier is restricted, or your liquid line is restricted.
Evaluate all of the system's operating characteristics to isolate the restriction.

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if there is a leak then of course you will get overheating from the engine..Be very careful as this can cause permanent damage to the head gasket and it will cost a lot more to fix..First try to stop this leak before you proceed further.

You have to find the motor that controls the blend door and open it manually to find out which one is bad there are 3 blend doors on the HV/AC system one will be where the heater core is. The other will be between the vented air and AC? heating system then the third door will operate vents in dash and defrost condition. If you have someone operate them AC system heating system and watch the blend door motors, the one you find not moving will be the one that has the problem. They have vacuum and electrical motors, if it is a acuum motor you can move the door manually with your hand, if it's electric you will have to disconnect the rod by removing the pinch clip off of the rod.

The Air-conditioning needs to be re-gassed. Take the car to an Auto Mechanic to get the Air-Conditioning re-gassed. They might also need to check it for leaks to make sure the gas stays in.

your car has two electric cooling fans one is specifically for the added heat load the A/c puts on the system. . This fan isn't turning on...check your fuses and the fan relays

sounds like the unit is low on charge.you will need a pro to check it

1. check your fan belt, if your fan belt is in the normal position and no problem.
2. check your compressor and also check the clutch, it is locate right in front of the compressor, when you turn on your air conidition, the clutch should be turn with the fan belt. If it is not, that means your compressor had problem.
3. check fuse.
4. check the freon small flow window see if the lique bubbling too much, if it is means you need fill up R-12 freon.
5. you probably can not do it yourself, in case if you need freon and your compressor is completely empety, you need a special tool to **** the air out first and than fill up freon.
6. if your air condition is leaking,and you have to fill up a can of special check leaking freon with red colour first, until you find the leaking parts, fix it then you can fill up freon