What happens if you have a bad cooling fan relay?
The check engine light illuminating may indicate a faulty cooling fan relay. A faulty cooling fan relay can also negatively affect air conditioning (A/C) performance. The reason being, on most vehicles, is that the cooling fan doubles as a condenser fan.
What should the resistance of a fan relay be?
A normal relay’s resistance will read between 40 to 80 ohms. Higher resistance levels warn that the coil has started to fail while lower readings mean the relay has broken down. Still another DIY test involves shaking the cooling fan relay and listening for any noises.
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 are the voltage ratings on a relay?
The switching and contact pins of the relay have their respective Maximum voltage and current ratings/Parameters. These Parameters are generally in-scripted on the plastic or PVC case of the relay.On the contact ratings, they will frequently have something like 5A@250VAC / 10A@12VDC.
What happens when a cooling fan relay fails?
If the relay fails, it will be unable to supply power to the fans, and as a result they will not operate. This can lead to overheating, especially when the vehicle is at a stop, where there is no forward motion by the vehicle to pass air over the radiator. 3. Cooling fans stay on at all times
When to test a radiator cooling fan relay?
If no power is observed at either 87 or 30, the fusible link or maxi fuse has shorted. Example: Testing the radiator cooling fan relay, the cooling fan should be operating. Step 14 – When replacing a relay be sure to match up the terminal location from the old relay to to the new unit.
What are the different types of fan relays?
There are several types of cooling fan relays. Their main difference involves the winding armature that they use to complete an electrical circuit. The most common type of relay uses an open armature. When the relay coil gets energized, the armature closes. The completed circuit allows the current to flow to the fan motor.
Where is the cooling fan relay located on a car?
When the cooling fan relay gets its signal from the ECM, the wiring diagram will typically resemble the following illustration. The cooling fan relay is normally located in either the underhood fuse and relay center or mounted to the electric fan assembly behind the radiator.
What to do if your radiator cooling fan Wont Stop Running?
Remove the lid. Look on the inside of the lid and for the mapping of the fuses and relays with their location. 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.
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.
Can a radiator fan and condenser fan share a relay?
There are, however, some models that use a dedicated second unit to the condenser. In such a scenario, the condenser fan and radiator fan may or may not share the same relay. If the cooling fan does not engage, you can check whether the relay is to blame by swapping it out for a different relay.
The check engine light illuminating may indicate a faulty cooling fan relay. A faulty cooling fan relay can also negatively affect air conditioning (A/C) performance. The reason being, on most vehicles, is that the cooling fan doubles as a condenser fan.
Why are the cooling fans not working on my car?
Many other issues can cause the engine to run hot or overheat. Rather than uncommonly high engine temps, the driver may notice that the cooling fans have stopped running. A faulty or broken relay cannot deliver power to the cooling fans. In turn, the unpowered fans won’t run, leaving the radiator to its own devices.
Why are the cooling fans not working on my 2006 Chevy Silverado?
2006 chevy Silverado Electric cooling fans do not come on. Replaced all relays. Checked the fans by hot wiring them to the battery and they function. Other than the PCM what else could it be? Clicking this will make more experts see the question and we will remind you when it gets answered.
There are, however, some models that use a dedicated second unit to the condenser. In such a scenario, the condenser fan and radiator fan may or may not share the same relay. If the cooling fan does not engage, you can check whether the relay is to blame by swapping it out for a different relay.
What causes a bad or failing blower motor relay?
Blown fuses. One of the first symptoms of a bad or failing AC blower motor relay is a blown AC blower motor relay circuit fuse. If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current…
A normal relay’s resistance will read between 40 to 80 ohms. Higher resistance levels warn that the coil has started to fail while lower readings mean the relay has broken down. Still another DIY test involves shaking the cooling fan relay and listening for any noises.
When do you need to troubleshoot a relay?
That is, on a horn, 12V should always be present on 86, and 85 is grounded when the horn button is pressed). If the control side fails either of these tests, you must troubleshoot the wiring. Often it is a problem in whatever is switching the control side on and off.