Why is my Mercedes radiator cooling fan not working?

This feature is not available right now. Please try again later. This is a very common problem with the Mercedes radiator cooling fan running constantly on high speed. The problem in most cases is a bad ecm so in order to fix it the ecm will have to be replaced and programmed to work with your vehicle. Check the mass airflow sensor first.

Why is my engine cooling fan running at constant high speed?

There is no Schraeder valve on the sensor and removing the sensor allows the gas to escape into the atmosphere. Replace the sensor and confirm good location of the wiring connector. Locate wiring in order to avoid chafing of harnesses. Use the AssistPlus to check the reading in the climate control module.

How to diagnose and fix continuously running cooling fan?

HOW TO DIAGNOSE & FIX CONTINUOUSLY RUNNING COOLING FAN EVEN THE ENGINE STOP! – YouTube If playback doesn’t begin shortly, try restarting your device.

Why does my C300 4Matic run full speed?

I am a new owner of a 2010 C300 4Matic that I bought from an insurance auction – the car was a salvage car due to a front impact. I have repaired all of the damage, but there is one issue that I cannot figure out. Immediately upon starting the car, the radiator fan begins to run full speed, even though the car is stone cold. The AC is OFF.

What should the radiator fan be running at?

The fan continues to run at its maxiumum speed, regardless of the engine temperature. I allowed the car to run today from cold to just above 80 deg. C before sutting it off today.

Why does my air conditioner not run cold?

The customer complaint is that the cooling fan runs constantly and that the air-conditioning is not as cold as usual. This problem is often caused by a faulty pressure sensor located on the air-conditioning condenser. If accessing fault codes, there are no relevant DTCs stored in the engine control module (ECM) or signal acquisition module (SAM).

Why does my radiator fan run full speed when I start the car?

Immediately upon starting the car, the radiator fan begins to run full speed, even though the car is stone cold. The AC is OFF. The radiator and condenser are BRAND NEW. This problem existed before and after the radiator was replaced. The fan continues to run at its maxiumum speed, regardless of the engine temperature.

How to repair a cooling fan in your car?

Cooling fan. How to repair a cooling fan in your car DIY with Scotty Kilmer. How to inspect and repair a cooling fan that’s not working. There’s many reasons why a cooling fan could stop working, such as a bad sensor, relay, fuse and more. DIY car repair with Scotty Kilmer, an auto mechanic for the last 42 years. 1.

Why is my car cooling fan running all the time?

Assuming the fan doesn’t run on it’s own with the key off, you may have an issue with the coolant temperature sensor signal. If the sensor’s signal is much hotter than correct or goes out of range then it will turn the cooling fan on all the time, although you would normally expect a code to set.

What to do if your cooling fan won’t turn on?

Pull the cooling fan relay out of the box. Replace the cooling fan relay with a new one. A stuck closed relay is the only thing that can operate the cooling fan continuously with the key off. The computer looses power with the key off and the same applies to the coolant temperature sensor.

Why does my Mercedes-Benz A / C blower run uncontrolled?

But under fault conditions it could fail as ‘always on’ or ‘never on’. Mostly (according to this forum) a failed BR causes the a/c blower to run uncontrolled. Btw your WIS a/c circuit diagram is not identical to mine for W208. However the blower motor/regulator part is the same.

Is it OK to leave the cooling fan on when the engine is turned off?

Car Fan Still On When Engine is Turned Off You park your car, turn off the ignition and start walking away. Then you notice the engine cooling fan is still running even though the car is turned off. It is ok for the engine cooling fan to keep running for a few minutes after turning off the car.

What are the signs of a bad cooling fan?

Common signs include the engine running hot and cooling fans either not functioning or running all the time. 1. Engine running hot 2. Cooling fans do not function 3. Cooling fans stay on at all times Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool.

Why are my cooling fans running at all times?

3. Cooling fans stay on at all times. If the cooling fans are staying on at all times, this is another (less common) symptom of a possible problem with the cooling fan relay. If the relay shorts internally, it may cause power to be permanently switched on, which will cause the fans to run at all times.

Why is my Mercedes air conditioner not working?

Your Mercedes vehicle will flash a host of service lights to inform you when something might be damaged inside the car. If the air conditioner unit is not running normally or is only blowing out warm air, it may be a temporary fault. Sometimes the unit isn’t actually damaged, and resetting your climate control unit …

When did the Mercedes Benz ML Class come out?

In this article, we consider the first-generation Mercedes-Benz M-Class / ML-Class (W163), produced from 1997 to 2005.

How can I tell if my radiator fan is working?

When a radiator fan works it usually makes a whirring sound that is easily noticeable. However, the radiator fan does not always start spinning on ignition. The ECU signals the radiator fan to work at the precise time. So, do not worry if the fan doesn’t immediately start working. Visually check the fan if you don’t hear its noise. 1. Broken Fuse

What to do if your Mercedes cooling fan keeps running?

To avoid this, cancel and sign in to YouTube on your computer. Automotive information based around Mercedes-Benz information and repair assistance along with other makes and models. No matter what car you own or need help with, my tips and tricks and teachings can help you along the way.

How to troubleshoot your Mercedes Benz air conditioner?

Identify the location of your compressor. Look at the pullyer and you should be able to see if it spining or not. The engine running turn the A/C on max cool, set fans high, and make sure that the clutch is engaging on the compressor. The pulley spins any time the engine is running. The center part of the A/C pulley only engages when the A/C is on.

In this article, we consider the first-generation Mercedes-Benz M-Class / ML-Class (W163), produced from 1997 to 2005.

Why does my air conditioner spin when the engine is running?

The pulley spins any time the engine is running. The center part of the A/C pulley only engages when the A/C is on. If the clutch is engaging and disengaging rapidly, the refrigerant may be low. Locate the Low Pressure A/C recharge port.

Where is the regulator on a Mercedes fan blower?

The Mercedes Benz fan blower motor regulator is a series of resisters in a printed circuit board about 2-inches square located right next to the blower motor.

Why is my car AC not working after recharge?

There could be numerous reasons for the improper AC working after you recharge it. You can handle the situation by finding out the most common reasons for this right away! 1. The Compressor is Unable to Connect Numerous reasons can cause the compressor to not to connect with the vehicle AC.

Why are the cooling fans not working on my car?

1. Engine running hot 2. Cooling fans do not function 3. Cooling fans stay on at all times Average rating from 129,472 customers who received a Vehicle Engine Cooling Inspection. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool.

What are the symptoms of a bad or failing fan clutch?

As the fan clutch is a cooling system component, any issues with it can cause overheating and other issues. Usually a bad or failing fan clutch will produce a few symptoms that can alert the driver of a potential issue.

What are the symptoms of a bad cooling fan relay?

1. Engine running hot One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. If you notice that your engine is running at higher temperatures than normal, that may be a sign that the relay is not functioning properly.

Where is the fan regulator on a Mercedes Benz?

These sensors even sense when the window is down or the door is open and increase the fan speed as necessary to maintain a constant temperature within the car. Remove the passenger side, lower dash cover under the glove compartment that conceals the blower motor. A 1/4-inch socket will be needed to remove the screws holding the cover.

What kind of fan does a Mercedes Benz have?

Click to expand… There are two types of fan, the one with the control unit attached is item 80 in this pic, control unit goes faulty, fan runs none stop and eventually the bearings collapse.

How do I stop the engine cooling fan?

If you start the engine and the fan starts to run then press EC or 0 and the fan stops, then switch the engine off key and start the engine again, do you need to press EC or 0 again to stop the fan? If so, can you borrow an A/C control unit to test with, this way we will know if it is the control unit or the wiring. Not open for further replies.

How much does it cost to replace a Mercedes cooling fan?

The fan is fairly easy to get on and off. It’s 4 bolts on your model year, but your space is constrained by radiator hoses and such. Here in the US, we can replace the whole fan assembly (fan and controller) for around $250, no labor included. Op: Have you resolved the noisy cooling fan issue?

What are the symptoms of a bad AC fan control module?

2. Cooling fans not running at all If the cooling fans are not coming on at all, then this may also be a sign that the fan control module is damaged. Without the cooling fans running properly, you will be at risk of having the car overheat. Running a car hot for a long period of time can lead to other damages like a blown head gasket. 3.

Category: Mercedes Hi Stan, The fan has 2 wires on it, vin: WDBNG75J8YA084049 . . I guess what I really need to know is the sensor, relay, fuses, etc.. that controll the fan so I can check / measure their function…

Is it OK to turn AC off on Mercedes Benz?

On some older Benzes, it is ok for temperature to rise with AC off, to reasonable extent (102C) of course. At this point, fan actuation must be checked with Star Diagnosis. I think the Fan module does not actuate the fan at lower end of output request. When temperature is below 100C- fan output request could be under 10% of full power.

How to troubleshoot your Mercedes medic air conditioner?

Turn the A/C ON. If you have an Economy button make sure that is off. Make sure fan is on HIGH, temperature selector is turned all the way to COLD, and that the A/C and recirculate light indicators are on. Set the temperature to cold, the lowest setting. Set the cooling fans on high on the climate control.

Why is the ECM not working on my Mercedes?

It seems very strange that ECM does not actuate the fan at 95 in the cluster, since one sensor is used for both. If you get a year warranty on the rebuilt transmission, that is a good deal, since the repair will cost as much, but will immobilize the car for a while.

Why is my air conditioner fan running at high speed?

This problem is often caused by a faulty pressure sensor located on the air-conditioning condenser. If accessing fault codes, there are no relevant DTCs stored in the engine control module (ECM) or signal acquisition module (SAM). • Run a Quick Test to check for any relevant fault codes.

Why does my Mercedes car keep running hot?

They’re designed that way, to keep your peace of mind. In reality, your engine temperature is always going up and down, that’s why there’s a thermostat in the car; to help stabilize the temperature and keep it in the range where your engine operates best. Mercedes didn’t do that.

Where is the coolant fan relay located in a Mercedes Benz?

The coolant sensor is just one of them. It also looks at A/C refrigerant pressure and the outdoor ambient air sensor as well. Both the ECU and the climate control modules can directly control the fan and it’s speed. The fan itself is intelligent and has it’s own module as well.

Where are the fuses on a Mercedes C class?

Fuses 43-63 are located under the hood. Near the hood hinge on the driver’s side. Take a look at the pictures for the exact location.

How often does a car cooling fan stay on?

Cooling fans stay on at all times Average rating from 129,472 customers who received a Vehicle Engine Cooling Inspection. Most modern vehicles use electric cooling fans to help pull air through the radiator so that it can keep the engine cool.

When does a computer turn on a cooling fan?

When the temperature exceeds a specific value — usually 215 degrees Fahrenheit — the computer will turn the fan on. The operating components in the cooling fan circuit include the cooling fan fuse, relay, coolant temperature sensor and the computer.

Is the Mercedes C230 single engine cooling fan working?

Mercedes C230 Single Engine Cooling… Mercedes C230 Single Engine Cooling Fan is Not Working Large Wires Red and Black have 12 volts and Good Ground. Small Wires have 12 volts pos and 3.1 volt Ground.

Why is the radiator cooling fan not turning on?

On your model, this module is separate from the fan assembly. Usually they malfunction. ECM sends control signal to this module depending on the engine temperature. Theoretically temperature sensor can be bad, but in this case engine performance would not be satisfactory as well. OK here is the scoop……

Is the cooling fan on my C240 4 MATIC working?

My 2004 C240 4 matic cooling fan runs at high speed at all times when the engine is running. As far as I can tell the coolant sensor is Ok and the Module is ok,it is setting a P0273 code. There are no … read more

Why are the buttons on my climate control not working?

If you pay close attention, you may notice that the button doesn’t spring back. This is caused by a broken plastic on the back of the buttons. This may often be misdiagnosed as a bad climate control unit and some mechanics will replace the whole climate control unit, but that is not necessary. It is possible to repair the broken buttons.

What to do if your Mercedes AC unit stops working?

Be aware that if you reset the unit and it again stops working, you need to take the vehicle in to the dealership for repairs. Insert the key into the Mercedes ignition and turn the ignition cylinder to the “2” position. This is as far as the cylinder will go without cranking the engine.

Why is the cooling fan running on high?

2007 Mercedes clk350 , why… 2007 Mercedes clk350 , why is cooling fan running on high ? As soon as car starts the cooling fan runs high, have checked ac temp sensor (is good) …still runs high regardless if ac is on/off.

What causes a car fan to run on it’s own?

If you have a thermostat fault code setting it can cause the fan to run, the code needs to be diagnosed and repaired. If the fan runs on it’s own without the key in then that’s a completely different situation. That can only be caused by the fan relay, a short on it’s control circuit, or bad ECM.

Why does my car fan keep running when the car is turned off?

Look in your owners manual. I think it’s primarily for cold weather, it keeps the car interior warm until the heater core completely cools down. Not to say you don’t still have a problem separate from that. It keeps running for hours unless I unplugged the battery or the motor itself. That is the design.

Why is my engine cooling fan running all the time?

Recently my cooling fan has started running continually and is quite noisy. The engine temperature is no different than before the fan started to misbehave. This is an electric fan. What controls this fan? and what would cause it to run all of the time?

Click to expand… There are two types of fan, the one with the control unit attached is item 80 in this pic, control unit goes faulty, fan runs none stop and eventually the bearings collapse.

What should I do if my engine cooling fan is running at high speed?

Replace the sensor and confirm good location of the wiring connector. Locate wiring in order to avoid chafing of harnesses. Use the AssistPlus to check the reading in the climate control module. As the system is still currently empty, this should read 0 bar. Fill the system with the specified amount of refrigerant and oil.

Why does my C320 CDI sport fan keep running?

New to the club guys but my C320 CDI sport has just developed a loud and constantly running engine fan. It stops when I turn off the engine but when I turn it on – it kicks in after 10 – 15 seconds. I have booked in but I worry as the MB garages are overly expensive…

Where is the relay on a radiator fan?

The fan relay is often located in the engine bay’s fuse box, but the best way is to check your repair manual to find where it is located. Testing a 4 pin relay is often very straightforward. Remove the relay and give 12 volts to pin 30 and 85. Ground pin 86 and check if there is voltage coming out from pin 87.

What causes out of balance readings on Mercedes?

Using the wrong spark plugs or aftermarket filters can contribute to out-of-balance readings that will add up to a failure. Having an accurate vehicle service history might give some clues as to the cause of a fault.

Why does my Mercedes have a fault code?

With each increase in data transfer protocol, or bandwidth, the integrity of the wiring has been the limiting factor for reliable and efficient operation. Since the system uses digital technology, even a small hiccup will cause miscommunication, false signals and fault codes. This is probably why we see code descriptions like “implausible.”

What to look for in Mercedes Benz diagnostics?

When looking for driveability faults, pay close attention to breather hoses (pinch the breather hoses at several points to see if they have turned to mush), air intake leaks (especially where the intake tube connects to the throttle body) or anything that would cause false readings from the MAF (like a damaged harness or connector that’s loose).

When does the engine cooling fan run on a S500?

On my S500 the fan only runs if the AC is ON. If the AC is OFF the fan only runs when the engine gets hot. I think this is standard on European specification cars, not sure about others. My fan runs all the time unless I activate the EC or the 0 buttons. Check for the codes via the display, none is back yet.

Where are the fuses on a Mercedes Benz are class?

Cigar lighter (power outlet) fuses in the Mercedes-Benz R-Class are the fuses #43, #44, #45 and #46 in the Luggage Compartment Fuse Box. The fuse box is located on the passenger side of the instrument panel, behind the cover. The battery compartment prefuse box is located next to battery under the front passenger seat.

Why is my Mercedes radiator fan running on high speed?

Please try again later. This is a very common problem with the Mercedes radiator cooling fan running constantly on high speed. The problem in most cases is a bad ecm so in order to fix it the ecm will have to be replaced and programmed to work with your vehicle. Check the mass airflow sensor first.

Why is my cooling fan running non stop?

Cooling fan system running non-stop The cooling fan module is supposed to cool the car parts when they get too hot. They do this until the temperature comes down to normal levels. If your cooling fans do not stop even after the temperature has been regulated or even when the car has been switched off then it is probably faulty and needs repair.

What should the current be on a radiator fan?

Start by unplugging the wires. There will be two wires of positive and negative feed. They should be putting out around 12 volts of direct current. Use a voltmeter to check that there is current present. If there is not, you need to check both the wires and the fan relay to see if replacement is required. The fan relay will be under the hood.

How long does the radiator fan stay on in a 2010 F150?

2010 ford f150 radiator fan stays on 2010 Ford F150, Radiator fan seems to be running on high more than it should. Fan kicks on about 30 seconds after vehicle is started and is extremely loud. Even kicks on when its a cooler day.

Why does my Mercedes air conditioner keep blowing hot air?

In many models, the AC keeps blowing hot air even after recharging the coolant. It is a frustrating problem, especially during the summer, when it is almost impossible to drive a car without the AC on. A Mercedes air conditioning reset is a possible solution. Do you know how to do it? Is there any other way to fix the glitch?

Why does my Mercedes E320 AC not reset?

For example, if you want to know about Mercedes E320 AC reset, it is better to check the manual and follow the manufacturer’s recommendations. If a Mercedes air condition reset does not work, these following reasons could be causing the trouble: When the AC is releasing hot air, the possible reason could be a defect in the damper.

Why is the battery on my Mercedes Benz not working?

Hint: Starter Problem or Low Battery This may seem obvious, but an old battery is the root of many headaches and can cause all sorts of malfunctions on Mercedes-Benz cars. How old is the battery on your Mercedes-Benz?

How can I tell if my Mercedes Benz air conditioner is working?

Since cars like the Mercedez Benz are designed to have the radiator cooling fan kick in when the A/C is on, make sure to check if the cooling fans on the radiator are working when the air conditioning is turned on. Identifying the location of your compressor is another way to check if the clutch is engaging on the compressor.

How to troubleshoot an electric cooling fan problem?

1.Has the Cooling Fan Actually Failed? 1 If the fan comes on when the AC is running at MAX, but doesn’t run when the engine is hot, check the temperature sensor… 2 If the fan fails to come on, first check for a fan blown fuse or triggered breaker. On older vehicle models, you may… More

Why does the radiator fan not come on when the AC is on?

In order for the AC Condensor to do its job it must stay as cool as it can. As for the engine coolant temp sensor, if the coolant is not hot enough to make the fan come on, then there is no need for the fan yet and there is no problem.

What to do when your air conditioner wont turn on?

What to do if your Mercedes Benz fan is stuck?

Not hard to do, just drop the blower motor and replace the regulator. The hardest part is positioning your self under the dash and looking upwards to locate the mounting screws. Hi Paul, just wondering if you found a solution to your stuck fan.

When to turn off the air conditioner in a car?

Click to expand… The blower is supposed to stay on for a few minutes after the car is off. Look in your owners manual. I think it’s primarily for cold weather, it keeps the car interior warm until the heater core completely cools down. Not to say you don’t still have a problem separate from that.

Why does my AC fan not come on?

When the ac is of the radiator hoses both become same heat after a while and the overflow reservoir starts boiling over and the fan do not kick in. Any advise please. You might have an initial temperature sensor which causes the fan to come on when the temperature begins to rise; that sensor might be defective.

How does a radiator fan work when the AC is on?

The electric radiator cooling fan assembly is controlled by a thermoswitch located in the side of the radiator. At higher coolant temperatures, the switch closes to start the cooling fans. Any time the coolant temperature rises to higher than normal levels, the fan will start and continue to run until coolant temperature returns to a normal range.

Why does my Jetta not have a cooling fan?

Simply the engine is not hot enough to turn on the cooling fan, its not hot enough outside, you are driving getting plenty of air flow through the grille to keep things cool without the assistance of the fan. Its possible that you have no problem at all. Was this answer helpful? I got a 2002 Jetta the cooling fans don’t turn on .

What should I do if my SSR cooling fan does not work?

You have 3 wires going to the cooling fan. 1 is low speed, one is high speed and one is black for ground. This may or may not work in AC mode and you may have to wait till truck begins to run hot. Try with truck running and AC on. Hit hard with something on the cooling fan motor body itself.

What should I do if my truck cooling fan doesn’t work?

How to test a Mercedes Benz fan blower motor regulator?

This is the blower motor resister, which controls the fan speeds. Disconnect the multi-wire connector from the blower motor resister next to the blower motor. Start the car and turn the air conditioning on. Test the connector for power at the terminals in the connector using the voltmeter. If there is power, reinstall the connector to the resister.

Why does my car fan keep running after I Turn Off the engine?

Running cooling fans help cool down the engine even after you turn off the car. Common Causes. If your cooling fan runs for over 10 minutes after turning off the engine, you may have a problem that needs to be fixed. Here are some possibilities causing the fan to stay running longer. low coolant level, faulty coolant temperature sensor,

Where is the resister on a Mercedes Benz fan?

Just to the left of the blower motor, an electrical connector connected to a flat 1-inch-by-2-inch plate can be seen. This is the blower motor resister, which controls the fan speeds. Disconnect the multi-wire connector from the blower motor resister next to the blower motor. Start the car and turn the air conditioning on.

Is there a problem with the Mercedes cooling fan?

Check the mass airflow sensor first. If it checks good then more than likely the ecm will have to be replaced. Loading…

Why is the cooling fan on my Volvo not working?

The cooling fan module is supposed to cool the car parts when they get too hot. They do this until the temperature comes down to normal levels. If your cooling fans do not stop even after the temperature has been regulated or even when the car has been switched off then it is probably faulty and needs repair.

What happens to the radiator when the a / C is turned on?

If it goes bad, your radiator fan usually won’t come on for normal operation, but will if the a/c is turned on. In the a/c circuit, you have F1 sending power to the low speed cooling relay (fender) and to the radiator switch.

What’s the jumper on a Volkswagen radiator fan?

Jumper 12V+ to the RED/BLK wire one at a time to +12V if the fan runs on both hi/low speed your fan is good. Reconnect the connector, and now measure for a good ground via resistance to the Brown Plug or the Case of the fan. 0 or .5 ohms, then you are ok, infinite, then you better get a new ground.

What happens when the radiator fan is off?

When the radiator fan is off, they are allowed to free open, so that the radiator has air flow across the width of the core. If they are missing then the Fan can draw engine air so much so that it can decrease the effieciency by half. lets move on to the Radiator Fans.

What are the headlamps on the new Mercedes E class?

Let there be light: The LED headlamps of the new Mercedes-Benz E-Class. Let there be light: The LED headlamps of the new E-Class. The high-resolution MULTIBEAM LED headlamps of the new E-Class will make traffic even safer. Improved illumination of the road.

Why is my Mercedes Benz W210 not working?

Old, worn out oxygen sensors can cause poor mileage, low power and a variety of fuel injection problems. Learn to replace them today with our article. The mass air flow sensor on the W210 is notorious for failing. Replacement is just a 15 minute job with this handy technical article. Over time, fuel injectors can get clogged and stop working.

Is the mass air flow sensor on the Mercedes-Benz W210 failing?

The mass air flow sensor on the W210 is notorious for failing. Replacement is just a 15 minute job with this handy technical article. Over time, fuel injectors can get clogged and stop working. Here’s a helpful article showing you how to remove them (complete with pictures too!).

Why is the fan on my Mercedes C230 not working?

Rebuilt Blower/runs hot wired to battery Checked fuses/relay New Cilmate control unit Used Resitor Pik n pull said it w … read more I have a “coolant visit workshop ” message on my 2006 mb c230 sport, I checked my coolant level, it is ok, but my fan seems to work only when the engine is cool.

When did Mercedes Benz stop making the 320?

Mercedes-Benz has sold a number of automobiles with the “320” model name: W124, W140, R129, W163, W210, C208. It is in production since 1993. W124 is the Mercedes-Benz internal chassis-designation for the 1984 to 1995/96 version of the Mercedes-Benz E-Class. The E320, E220, and E200 cabriolets ceased production in 1997.

Why is my Mercedes 300sdl heater not working?

I have an 1986 Mercedes 300SDL Turbo and can’t get the AC/Heater blower to work. Rebuilt Blower/runs hot wired to battery Checked fuses/relay New Cilmate control unit Used Resitor Pik n pull said it w … read more

Why is my a / C compressor not working on my Mercedes?

One other reason why the A/C compressor does not engage is the fact that the system may be low on R134 refrigerant. Typically older cars may have very slow leaks that may require top off with refrigerant every couple of years. You can use a R134a recharge kit to recharge your system if the A/C compressor is not working.

Is the 2007 Mercedes clk350 a 2007 Mercedes?

Yes, I did see your vehicle information and that it was a 2007 Mercedes. You can do the work and then come back if you’d like. Let me know if you need any more help!

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