Why are my radiator fans not turning on?
This is why the fans go on. Normally this means that the wiring and the PCM (which turns on the fans) is functioning. I would suspect a faulty sensor, but it was replaced. There could be a problem in the wiring to the PCM. High resistance or a partially broken wire causing the temp sensor signal to the PCM to be skewed / inaccurate.
Why is the coolant sensor on my radiator not working?
There could be a problem in the wiring to the PCM. High resistance or a partially broken wire causing the temp sensor signal to the PCM to be skewed / inaccurate. You need to have a scanner on it to look at what the PCM is showing as the coolant temp.
Why do my fans go on when I unplug the PCM?
Answer: Unplugging the sensor causes the PCM to default the coolant temperature as -40 degrees F. This is why the fans go on. Normally this means that the wiring and the PCM (which turns on the fans) is functioning.
Is there a way to test a radiator fan?
You can test the electrical radiator fans by taking a wire from the car battery, unplug the radiator fan connector, and put 12v+ and ground into the connector. This is the fastest and easiest way to test your radiator fans. Because the radiator fan is often drawing so much power, there is often a relay that is powering the coolant fan.
What happens when I unplug the temperature sensor?
The fan still inst working, however if I unplug the temperature sensor the fan works from start up. The fan also works when the A/C is on. What could be the problem? have the same problem? Fan will default to on with no signal from the sensor, the only other item would be the fan control module.
How does a coolant temp sensor work on a fan?
Coolant Temp Sensor – LH head. I have used a t-stat housing mounted fan switch with excellent results. Sounds like you hooked up a gauge to a temperature switch. That’s a problem right there. A gauge won’t run off a temperature switch. Also that temp switch supplies the switchable ground connection to the fan relay.
Where do I find the fan temp switch?
The easiest place to first check would be in the relay socket. We know the circuitry and fans are ok, since they work with the a/c and DLC. It is just a matter of whether the PCM is commanding them on by temperature. It could end up being a PCM issue.
Why is the temperature sensor on my radiator not working?
Any added resistance from corrosion or a loose pin can cause a problem. You say you changed the sensor, how about an odd test. Unplug the sensor wiring and plug in the old sensor. Now just turn on the key and use a small torch or even a candle to heat the old sensor on the area that was inside the engine.
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
Can a bad coolant sensor cause a car to not start?
Some cars use the engine coolant temperature sensor to control the electric cooling fans. You have two separate temperature sensors for the fans, dashboard gauge, and engine management in most cars. However, if your car has a single sensor, a bad engine coolant temperature sensor may result in your fans won’t start at all.
This is why the fans go on. Normally this means that the wiring and the PCM (which turns on the fans) is functioning. I would suspect a faulty sensor, but it was replaced. There could be a problem in the wiring to the PCM. High resistance or a partially broken wire causing the temp sensor signal to the PCM to be skewed / inaccurate.
Why does my water pump fan not come on?
Ok, so unpluging the ETC sensor in the water pump allow the fans to run. When the ETC sensor is plugged in the fans will not come on. I then replaced the ETC sensor with a new one but the fans will still not come on with it plugged in. Anyone have any other ideas? oke:
Some cars use the engine coolant temperature sensor to control the electric cooling fans. You have two separate temperature sensors for the fans, dashboard gauge, and engine management in most cars. However, if your car has a single sensor, a bad engine coolant temperature sensor may result in your fans won’t start at all.
What should the temp of the coolant sensor be?
Check that the temperature value of the CTS is around 80-90c when the engine is hot. A lot of engine coolant temperature sensors have two wires and the sensor is controlled by Ohm. Get a wiring diagram and find out what ohms you should have at a specific temperature to check the function.
Check that the temperature value of the CTS is around 80-90c when the engine is hot. A lot of engine coolant temperature sensors have two wires and the sensor is controlled by Ohm. Get a wiring diagram and find out what ohms you should have at a specific temperature to check the function.
Answer: Unplugging the sensor causes the PCM to default the coolant temperature as -40 degrees F. This is why the fans go on. Normally this means that the wiring and the PCM (which turns on the fans) is functioning.
What happens if your coolant level is low?
If your coolant level is low, there is a chance that you will get air in the system, and the coolant temperature sensor will not read the coolant temperature correctly. If the coolant level is low, you need to refill the coolant to optimum levels. Failing to do so could risk your engine becoming overheated and seized.
Why does my car have a bad coolant temperature?
If you have to pump the gas pedal in the morning to keep your car running, you may have a bad engine coolant temperature sensor. The computer in every fuel-injected car must know two things before it can figure out the correct cold-start air/fuel mixture: the engine coolant temperature and the outside air temperature.
There could be a problem in the wiring to the PCM. High resistance or a partially broken wire causing the temp sensor signal to the PCM to be skewed / inaccurate. You need to have a scanner on it to look at what the PCM is showing as the coolant temp.
If your coolant level is low, there is a chance that you will get air in the system, and the coolant temperature sensor will not read the coolant temperature correctly. If the coolant level is low, you need to refill the coolant to optimum levels. Failing to do so could risk your engine becoming overheated and seized.
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.
Defective temperature switch, coolant sensor or other sensor. Engine thermostat is stuck OPEN (engine never gets hot enough to turn on the fan) Faulty fan relay. A wiring problem (blown fuse, loose or corroded connector, shorts, opens, etc.)
Why is your radiator fan not running?
The most common causes when a radiator fan is not coming on is broken fuse, bad wirings, bad coolant temperature sensor, bad fan relay, or a faulty radiator fan . Here is a more detailed list of the most common causes of a radiator fan not coming on.
Why does radiator fan not working?
the first thing to check is the fuse. If you don’t know where the…
What is the best radiator fan?
List of Best Electric Radiator Fan in 2021 UPGR8 Universal 12 Inch High-Performance Slim Cooling Fan, (Black) We finalize our review with this High-Performance Slim Cooling Fan by UPGR8. AUTOSAVER88 High Performance 16 inches Cooling Fan Black Electric Radiator. AUTOSAVER88 12 inches Electric Radiator High-Performance Cooling Fan.
Why is the cooling fan not working?
If you think the cooling fan isn’t working because your temperature gauge is indicating overheating , open the hood, start the engine, and let it idle for 15 to 20 minutes. If the fan comes on, you may have a bad temperature sensor or gauge .
What should temp be when cooling fan does not come on?
NOTE: if the cooling fan doesn’t come on when the engine has been operating for 20 minutes or more, make sure that coolant is reaching operating temperature, around 220°F (104°C). You may be dealing with a stuck-open thermostat.
Where is the temp Guage and electic fan sending unit?
Installed the temp sender for gauge where the original one was installed on the driver’s side head. I also have A/C, so I installed a diode in the power lead to the fans to keep the current from “back flowing” to the relay when the A/C is turned on.