Dodge RamCharger Central banner
1 - 9 of 9 Posts

·
Registered
Joined
·
171 Posts
Discussion Starter · #1 ·
Hey all,
I normally am on here for my Ram Charger questions, but my wife drives the Durango and I am having a problem with the electric cooling fan staying on all the time, even when the engine is cool. The only way I could shut it off is by pulling the fan fuse. Well, this is fine for highway driving, but in stop and go traffic the engine can get pretty warm. Question is, does anyone know where the temperature switch/controller is located so I can check it?
 

·
Registered
Joined
·
171 Posts
Discussion Starter · #3 ·
I'll check it out. I know the temperature is reading, this should be an analog signal. I thought there may be a discrete temperature switch that shuts the fan off if coolant temp fell below a certain setpoint. UNLESS, the temperature sensor signal goes to the computer and the computer turns the fan on/off at a predetermined setpoint. I hope this isn't the case and it is just a temperature switch somewhere.
 

·
Moderator
Joined
·
7,995 Posts
There may be a relay in this circuit also?

ENGINE COOLANT TEMPERATURE SENSOR - PCM INPUT
The Engine Coolant Temperature (ECT) sensor is used to sense engine coolant temperature. The sensor protrudes into an engine water jacket.

The ECT sensor is a two-wire Negative Thermal Coefficient (NTC) sensor. Meaning, as engine coolant temperature increases, resistance (voltage) in the sensor decreases. As temperature decreases, resistance (voltage) in the sensor increases.

At key-on, the Powertrain Control Module (PCM) sends out a regulated 5 volt signal to the ECT sensor. The PCM then monitors the signal as it passes through the ECT sensor to the sensor ground (sensor return).

When the engine is cold, the PCM will operate in Open Loop cycle. It will demand slightly richer air- fuel mixtures and higher idle speeds. This is done until normal operating temperatures are reached.

The PCM uses inputs from the ECT sensor for the following calculations:


for engine coolant temperature gauge operation through CCD or PCI (J1850) communications
Injector pulse-width
Spark-advance curves
ASD relay shut-down times
Idle Air Control (IAC) motor key-on steps
Pulse-width prime-shot during cranking
O2 sensor closed loop times
Purge solenoid ON/OFF times
EGR solenoid on/off times (if equipped)
Leak Detection Pump operation (if equipped)
Radiator fan relay ON/OFF times (if equipped)
Target idle speed
 

·
Registered
Joined
·
171 Posts
Discussion Starter · #5 ·
Thanks Chump, your the best! I'll look into it and let you know what I find.
 

·
Moderator
Joined
·
7,995 Posts
Description and Operation

RADIATOR COOLING FAN RELAY - PCM OUTPUT
The radiator cooling fan relay is a 5-pin, solenoid type, mini-relay. It is located in the Power Distribution Center (PDC) . Refer to label on PDC cover for relay location.

The electric radiator cooling fan is controlled by the Powertrain Control Module (PCM) through the radiator cooling fan relay. The PCM will activate the relay after receiving inputs from the engine coolant temperature sensor and/or an air conditioning on/off signal.

Not Equipped With A/C: The relay is energized when coolant temperature is above approximately 103 °C (217 °F) . It will then de-energize when coolant temperature drops to approximately 98 °C (208 °F) . Refer to Cooling Systems for additional information.

Equipped With A/C: In addition to using coolant temperatures to control cooling fan operation, the cooling fan will also be engaged when the air conditioning system has been activated. Refer to Heating and Air Conditioning for additional information.

 

·
Registered
Joined
·
171 Posts
Discussion Starter · #7 ·
You wouldn't happen to have the wiring on that would you. Also, I know it says the relay is in the PDC center, but where the he** is that?
 

·
Registered
Joined
·
171 Posts
Discussion Starter · #9 ·
Cool, again, your the best! BTW, at the risk of offending other people on the site, I like your political slogan.
 
1 - 9 of 9 Posts
Top