Radiator fans will not work

It sounds like you are losing connection or the computer is not giving the command to close the relay. Lets use a test light to check the triggers and grounds.

Here is guide and the wiring diagrams to help you test the system:

https://www.2carpros.com/articles/how-to-use-a-test-light-circuit-tester

Check out the diagrams (below). Please run this test and get back to us.

Cheers, Ken

Hi and thanks for using 2CarPros. Com. It sounds like you have already done a lot of work trying to fix this problem. What I have done is this. The first picture I have attached is the coolant temperature sensor location. There are two coolant temperature sensors on this vehicle. One is for the gauge, the other is for the computer. Check to make sure you are getting the correct one.

Next, the second picture is a flow chart for checking the fan relay. The chart is specific to this vehicle and should help you find the problem. Please keep in mind, you mentioned in your post that you have power, signal, and ground. If that is the case, it should work. Something is happening when power is sent, otherwise the fans would work.

Check out the flow chart and let me know if you find the issue.

I hope this helps.

Joe

Good afternoon.

I attached a wiring diagram of the system. Check the fuse listed for power on both sides with the key on.

The engine coolant sensor is what sends a signal to the PCM. Based on that reading it will ground the control side of the relay and turn on the fans.

Roy

The first step is to diagnose the cause of the problem. There's three circuits to consider. The first is the coolant temperature sensor for the Engine Computer. That is not the same as the sensor for the dash gauge. The CTS tells the computer the coolant temperature, then the computer turns the fan relay on at around 210 degrees. That's the second circuit. The relay turns on the high-current to the fans. That's the third circuit and the one that usually develops the problems. The fastest way to diagnose this system is to use the Chrysler DRB3 scanner to command the fan to run. That will allow you to see the actual engine temperature to be sure the sensor circuit is working, and you can take voltage measurements in the relay circuit without having to run the engine.

Some people complained that they could actually hear the fan when it turned on. It wasn't very loud but in response the engineers came up with a continuously-variable-speed relay which is another unnecessary computer module and highly prone to failure. If you're going to guess and try random parts, the relay is the best suspect. It has four wires in the plug and usually sat halfway down along the left side of the radiator. There was a service bulletin related to it to check for broken mounting bolts. If they break the relay will seriously overheat. If it's still working it will get hot enough to burn you. It has to be bolted tightly to the body to dissipate the heat.

You need to get the cooling fan going-also could be airlock in the system if it continues get it block and pressure tested.

Hello, I'm Danny.

I've attached below step-by-step diagnosis/test instruction pictures below for that code. It sounds like you might be having a wiring or PCM problem. Let me know what happens after testing. Hope this helps and thanks for using 2CarPros

The first thing is to bypass everything and apply 12 volts directly to the fan motors to see if they run. If one is tight it is likely it caused a fuse to blow.

You can also check the fan system operation by unplugging the two-wire coolant temperature sensor while the engine is running. That will turn on the Check Engine light which will go out later but it will also cause the Engine Computer to turn on the fans because it doesn't know if the engine is overheating.

Hi:
If you replaced the relay, there are two things left to check. First, are you getting power to the fan motors when it heats up? If not, you need to check the temp sensor.

Let me know what you find.

Joe

Good question. Yes the fan will come on with the AC. Before you replace anything, check to make sure if you are getting power to the fan motors. Turn the AC on and check. If you have a 2 fan system, and I think you do, only one will get power. Check it with a volt meter if you have one to make sure, if there is power, you are getting 12 volts. If there is power to the fan motor, the motor will most likely be bad. You could also unplug the motor and run 12 volts to it from the battery to see if it turns on.

Let me know what you find.

Joe

Wow, now I don't know where to go. Is there another relay in the box with the same part number that you can switch with the fan relay. I wonder if you have a bad relay.