A cooling fan that keeps running continuously after switching off the engine is a common problem with the Peugeot 207. This can occur because the engine electronics detect a missing signal from the ABS (anti-lock braking system) or due to a fault in the control of the high-pressure system, which results in a heavy load on the battery. The ultimate end result: a blowing fan that keeps going, even when the car has been switched off for a long time. In this article you will discover why this happens and what you can do about it.
The Peugeot 207 is known among owners as a reliable compact car, but technical quirks such as a fan that keeps running are fairly common. The problem usually only occurs after parking, once you have already got out of the car and the engine noise has long since faded away. The fan, however, continues to run, producing a clear blowing sound that can last for ten to fifteen minutes. This not only leads to unnecessary discharge of the battery, but in the long term can also cause damage to the fan motor itself.
This phenomenon occurs in both petrol and diesel versions of the 207. The cause is usually electronic or sensor-related. The engine electronics of the car think that cooling is still needed, even though the engine has long since cooled down. The system remains active due to incorrect signals from sensors, faulty relays or problems in the electrical wiring.
Why does the fan keep running after parking
The main causes lie in the cooling system and the electronics that control it. In the Peugeot 207, communication between various control modules plays an important role. When the engine electronics do not receive a signal from the ABS system, this may be interpreted as a fault, triggering an emergency protocol in which the cooling fan continues to run constantly to prevent overheating.
The control of the high-pressure system for the air conditioning can also cause the fan to keep running. This system sometimes develops a fault. It also happens that the pressure values are not registered correctly. In both cases the fan remains active to cool the condenser. This mainly happens on warm days when the air conditioning has been used intensively.
‘ The sensor sometimes fails. ’
Faulty temperature sensor as a common culprit
The temperature sensor in the cooling system measures the temperature of the coolant and passes this information on to the engine electronics. This sensor is usually located near the thermostat and can be recognised by its green colour. The sensor sometimes fails. It then no longer sends correct information. The result: the electronics think that the engine is getting too hot and permanently activate the fan.
You can test this yourself by disconnecting the plug from the sensor. If the fan then stops running, you have found the cause. Replacing the sensor is relatively simple and usually takes no more than half an hour. When refitting, make sure you install the sensor in the same orientation as the original.
Fan relay that sticks
The relay is a switch that controls the power supply to the fan. With a correctly functioning relay you hear a clear clicking sound when the fan switches on or off. A faulty relay sometimes sticks in the closed position. Power is then permanently supplied to the fan, even when the engine is switched off and no further cooling is needed.
The relay is usually located in the fuse box under the bonnet. You can test it by listening for the clicking sound or by checking continuity with a multimeter. A faulty relay shows irregular resistance readings or has no continuity at all. Replacement is simple: pull the old relay out of the holder and fit a new one with the same specifications.
Problems with the thermostat
The thermostat controls the circulation of coolant through the engine. The thermostat sometimes gets stuck in the open position. The coolant then continues to circulate through the radiator all the time. This can cause the fan to run more frequently or for longer to dissipate excess heat, even when this is not actually necessary.
You can recognise a faulty thermostat by abnormal coolant circulation. The engine warms up slowly or does not reach its normal operating temperature. Check this by observing the engine temperature gauge while driving. Replacing a thermostat is a more technical job that requires the cooling system to be drained. It is preferable to have this done by a garage.
‘ Corrosion on the connectors can lead to intermittent or weak signals. ’
Check electrical wiring and connections
Loose or damaged wiring can cause incorrect signals that activate the fan. Reversed connections also occur, especially after work on the cooling system or after replacement of the fan motor. Check all visible wires and connectors for damage, corrosion or loose connections.
Pay particular attention to the connections of the temperature sensor, the relay and the fan motor itself. Corrosion on the connectors can lead to intermittent or weak signals. Carefully clean them with contact cleaner and make sure all connections are firmly seated. With reversed wiring, the fan may possibly run in the wrong direction, which you can recognise by reduced airflow.
How to stop the blowing fan immediately
You notice immediately after parking that the fan keeps running. In that case you can stop it by disconnecting the battery. However, this is not a permanent solution and should only be used as a temporary measure to prevent the battery from discharging. Disconnect the negative terminal with a spanner and leave it disconnected for a while.
You can also remove the fan relay from the fuse box. This immediately stops the power supply. Do not forget that you must refit it before you drive again, otherwise the cooling will no longer work while driving. These methods are temporary solutions until you have resolved the actual cause.
Is this a known problem with diesel Peugeot 207s
Yes, this problem occurs in both petrol and diesel versions of the Peugeot 207. In diesel versions, the problem is sometimes caused by specific software faults in the engine electronics that disrupt communication between different modules. Models built between 2006 and 2012 in particular frequently show this complaint.
In diesel engines, the high-pressure system for the fuel pump also plays a role. When the electronic control of this system develops faults, it can send incorrect signals to the cooling fan. This requires diagnosis with professional equipment that can read out fault codes. A dealer or specialist garage can perform any software updates needed to resolve this problem.
‘ You also need diagnostic equipment when fault codes have to be read or software needs to be updated. ’
When should you go to a garage
Although many of these checks and repairs can be carried out yourself, there are situations in which professional help is essential. You check the sensor, relay and wiring but do not find the cause. There may then be a deeper electronic fault. You also need diagnostic equipment when fault codes have to be read or software needs to be updated.
Also have a garage carry out an inspection if you suspect that there is engine damage due to overheating. This can occur when the fan does not work while driving, but then keeps running afterwards. Symptoms include excessively high engine temperature, loss of coolant or smoke from the engine bay.
Prevent problems with regular maintenance
You can prevent many cooling system problems with regular maintenance. Check the coolant level at least twice a year and top it up if necessary with the correct fluid according to the manufacturer’s specifications. Also pay attention to discolouration or contamination of the coolant, which may indicate internal problems.
Inspect all electrical connections annually for corrosion or wear. Clean them with contact cleaner and protect them against moisture. Also make sure the radiator remains free of leaves, dirt and insects that could obstruct the airflow. A clogged radiator results in poorer cooling and increased load on the fan.
Have the cooling system flushed every two years to remove sediment and contamination. This improves the efficiency of the system and reduces the chance of faults in sensors and the thermostat. Replace the coolant according to Peugeot’s maintenance schedules, usually every four to five years.
A fan that keeps running on your Peugeot 207 is annoying, but in most cases it is easy to resolve. By systematically checking the temperature sensor, relay, thermostat and wiring, you can usually track down the cause quickly. If you cannot solve the problem yourself, or if you are unsure about the diagnosis, contact a garage in good time to prevent further damage to the battery or fan motor.
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Frequently asked questions
The most common causes are a faulty temperature sensor that constantly requests cooling and a sticking or defective fan relay. In addition, a thermostat stuck in the open position and incorrect or damaged wiring/connections can cause the fan to keep running constantly.
Start with a visual inspection of wiring, plugs and the fan relay for damage, corrosion or loose contacts. Then disconnect the coolant temperature sensor (near the thermostat, often green): if the fan stops, the sensor is probably defective. With the ignition switched on, listen to whether the relay is clearly clicking and, if necessary, check it with a multimeter; no click or abnormal readings indicate a defective relay. Finally, check whether the engine reaches normal operating temperature and the coolant circulates correctly; if the engine stays too cold or circulation is abnormal, the thermostat may be stuck and needs to be checked/replaced.
Often the coolant temperature sensor (near the thermostat) and the fan relay are to blame, and sometimes the thermostat itself or poor wiring/connectors. Test the temperature sensor by unplugging it: if the fan then stops, the sensor is probably defective. Check the relay for an audible switching sound and use a multimeter to test continuity; a relay that “sticks” or has no continuity should be replaced. Visually check wiring and plugs for corrosion, breaks and loose contacts, and have the thermostat tested or replaced if necessary (circulation and opening temperature).
Yes, as a temporary solution you can disconnect the temperature sensor near the thermostat; if the fan stops, the sensor is probably defective. Another emergency solution is to remove the cooling fan relay, so the fan no longer receives power. Do bear in mind that you will then have no (or reduced) cooling and the engine can overheat more quickly when stationary. Only use this briefly and have the problem resolved properly as soon as possible.
Because the fan keeps running unnecessarily, the battery is constantly under load, causing it to discharge faster and age prematurely or fail. The alternator has to work harder to supply the required current, which can lead to additional wear over time. The fan motor itself may also wear out more quickly or burn out due to excessive operating time. Finally, relays, wiring and plugs can overheat or become damaged due to prolonged current draw.