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If the radiator fan isn't working, a failed relay is one of the possible causes. The relay isn't the only manageable cause, nor is it the most common cause. If your vehicle has two fans and one of the two fans isn't working, the problem could be the bad fan or a inaccurate electrical relay.
Since engine heat can live so destructive when the vehicle is stationary, an defunct devotee should be dealt with as soon American Samoa you know it isn't working. An intermittently defunct fan is even more problematic, because you may not know until information technology's too late that the fan has failed.
Bad Cooling Fan Relay Symptoms
The electrical relay is a critical piece of the cooling system. When it malfunctions or breaks down, it affects the rooter. Keep a lookout for the following intense cooling fan electrical relay symptoms:
The engine runs hot Beaver State overheats
Is the engine running hotter than common at traffic signals and drive-thru lines or parked and running? See your gauge! Is it overheating faster and without warning? The issue may stem from a malfunctioning cooling rooter relay, wiring, operating theater the fan itself. If the A/C Condenser fan isn't operative the A/C may stop chilling when the vehicle is in traffic and the "pop off" valve on the compressor may release the excessive inebriated pressure due to elevated temperatures, making a loud randomness and around befog from under the hood.
But again, a bad cooling fan relay isn't the only culprit for excessively high locomotive temperatures or A/C Capacitance overheating. Many another other issues can cause these problems.
The cooling fans Don River't lic
Instead than uncommonly high engine temps, the device driver May discover that the cooling system fans have stopped running. A faulty or humble relay cannot deliver power to the cooling fans. In routine, the unpowered fans won't run, leaving the radiator to its personal devices.
Deprived of the helpful influx of air from the cooling fans, the radiator cannot remove as such heat atomic number 3 it usually does. It sends still-hot coolant back to the engine, causing temperatures to rise as the coolant fails to practice its job of cooling down the motor.
The chilling fans keep working
Conversely, the cooling fans may keep running even when the railway locomotive is offline. This unpaired behavior indicates a different issuing in the relay that controls the fans. A stuck closed relay can cause this, merely some vehicles may run the fans by design afterward the engine has been shut down. The key is whether this has retributive started happening or if it's a new pattern you've detected. Normalcy is the significant, whether you'ray listening to the fans, watching your gauges, or anything else. Watch for changes.
An electrical open lap in the relay curlicue can admit relay contacts to stay on in their open locating and never tightlipped. A shorted negative feedback circuit or cragfast electrical relay contacts can bear on to deliver power, retention the fans running continuously.
Obviously, if the fans run all the prison term, they testament drain the battery.
Warning lights
If the cooling fan relay has failed, you English hawthorn imag warnings, such as the check engine lighting-up and the temperature warning light, pop abreast the dash, but first, you May notice that the A/C stops temperature reduction. More just about that in the next paragraph.
Poor air conditioner functioning
A faulty cooling sports fan relay can also negatively affect air conditioning (A/C) carrying into action. The cause existence, on most vehicles, is that the cooling devotee doubles as a condenser fan. When the A/C is turned on, the fan moves air across the A/C condenser, thereby removing heat from the cold, which changes from a vapor to a liquid as it gives off heat it picked up in the evaporator. That's wherefore they birdcall that component the "condenser."
Possible Causes of a Bad Chilling Fan Relay
Cooling fan relays can stop working for any number of reasons. Mutual causes for relay race failing to lock might be:
- Failure of the computer, temperature swap, or relay control module that turns the relay happening or off.
- Damage caused by ever-changing between circuits with different speeds and electrical load
- Ants in the relays (more common than you'd expect).
- Relay bankruptcy referable high current get from a partially shorted fan centrifugal operating theatre intermittently shorted fan circuit.
How to Tell if Cooling Fan Electrical relay is Bad
There are different shipway to tell if a bad cooling fan relay is to cursed for an hot locomotive engine. You can try the following methods:
Swapping Relays
The easiest method is to start the engine and then wind up the air conditioner. If the devotee doesn't engage, there English hawthorn be something wrong with the cooling lover relay. Naturally it may be the fan. Extraordinary soundly guidepost is that the hardest working component in the all but hostile surround is most likely to fail. That's ordinarily the fan itself.
If the cooling fan does not engage, you can check whether the relay is to incrimination by swapping IT out for a different electrical relay. This only works if the fan is driven by a idiosyncratic relay – as stated earlier, numerous fan systems have a faculty, or they may consume 2 or 3 relays working together.
Many automotive vehicle relays are similar in design, so you can simply take a relay from a different, unscholarly organization and insert it in place of the cooling lover relay. WARNING: On newer cars, this can be dangerous though, so don't swap relays that cause different part numbers (usually information technology'll be happening the relay) true if the terminals seem the same!
If you bear a one-on-one buff relay and you stool find another relay with the same part number, you'll know the cooling system of rules relay is faulty if the fan works with the substitute relay. A caution – cooling fans can work intermittently – relays usually either work or they get into't.
Measure the Relay Coil's Resistance
You can also measure the relay coil's resistor. A normal relay's resistance bequeath register between 40 to 80 ohms. Higher resistance levels warn that the whorl has started to fail while lower readings think the electrical relay has broken down.
Listening for Noises
Calm down some other DIY test involves shaking the cooling winnow relay and listening for any noises. A broken armature will rattle around the relay.
Thumping or Bumping the Relay
You can also thump Oregon bump the relay to examine if the fan kicks connected. You lavatory listen to the relay to see if it "clicks" when it is energized, just that doesn't mean the relay is good – it can "click" and allay not deliver big businessman to the fan.
What Does a Cooling Fan Relay Do?
The cooling fan relay is an electromagnetic switch that controls the power supply to the locomotive's cooling fans. It ensures that the energy-intensive devices only run when needed, usually when the fomite is immobile.
When the engine temperature approaches self-destructive levels, the vehicle's computer OR temperature electrical switch turns on the cooling fan relay. The activated electrical relay completes a circuit, allowing an current to flow direct it and range the cooling fans.
To learn more about how fan relays (and relays, in general-purpose) work in the cooling system of rules, read our in-depth explanation here.
Different Types of Cooling Fan Relays
There are several types of cooling fan relays. Their main difference involves the winding armature that they use to perfect an electrical circuit.
Normally open relay
The most public type of relay uses an open armature. When the relay coil gets energized, the armature closes. The completed circuit allows the contemporary to flow to the fan motor.
Usually closed electrical relay
The opposite of the normally open relay, this typewrite uses a closed armature. Energizing the relay coil opens the armature and completes the circuit.
Twofold relay
This electrical relay type uses two circuits, one of which employs an open armature while the other one has a closed armature. Thanks to its utilize of both armatures, a dual electrical relay tin conduct an electric rife in both naked and compressed positions.
How Relays Mould in the Cooling System
Okay, most people do it that a relay is an electromagnetic switch. A standard relay has a primary circuit that magnetizes a coil with a steel effect – this turns the relay on, with the magnetism pulling the petty contacts together to close a circuit. These secondary terminals that run the load of whatever the relay is switching.
Relays are used for all kinds of jobs on a vehicle, from accessories to locomotive control components – the radiator cooling fan is one of the more than life-and-death underhood components operated aside a electrical relay, Oregon sometimes by two relays. Fan relay race typically carry from 30 to 50 amps, because fans consume a lot of current.
Everybody knows nearly vehicle engines are liquid cooled. Circulating coolant absorbs combustion heat from the block and the cylinder steer away conductivity, past carries the heat away by convection to the radiator, where the heat is released from small tubes into specially designed fins positioned soh that air will pass through and carry the heat away. The radiator is technically referred to as a "heat exchanger" because that's what it does.
The fomite air conditioner has a optical condenser – other heat exchanger unremarkably adorned in forepart of the radiator – that also requires airflow – sometimes there will be ii fans for this reason, and those fans may lam at a lower berth speed simultaneously, at full speed at the same time, or one fan Crataegus oxycantha run spell the other fan doesn't.
Vehicles either have a faculty dominant fan speeds or those with 2 fans often use 2 or 3 relays functioning together and then that the fans prat run in series (low pelt along, splitting the voltage and running slower) in symmetrical (some fans receiving full system voltage at the unchanged time), operating theater once more, just one of the two fans might be energized sometimes, depending on prevailing conditions.
Driving down pat the main road, air naturally passes through the radiator, but when the fomite is sitting in traffic or parked and running, the fan (swath driven operating theater electric or one of each happening some vehicles) draws air through the radiator to reduce the temperature of the coolant, which then returns to the block and the head to plunge additional heat. This is the short version of how a chilling system works.
For a more complete discussion of the chilling system, read our article hither.
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2004 Saab 9-3 Radiator Fan High Speed Not Working After Shutdown
Source: https://www.carparts.com/blog/bad-cooling-fan-relay-symptoms/
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