Radiator Fan Not Working

[genesiskt]

Hello All, This may be answered somewhere already so I apologize for another thread. My husband is having issues with his radiator fan not working.
2018 Ram 1500 3.6

He changed the fan, that wasn't the problem, he changed the thermostat and the coolant tempature sensor as well as the PCM. None of those are the problem. He's at a loss and so am I. My brother in law the mechanic can't even seem to know what the problem is.

Can someone please give us another idea to look for? We truly appreciate the help.

 

[ibike]

Fuse? Do you get voltage to the fan? Check your grounds Jeep dodge fiat is really bad about losing grounds.

 

[genesiskt]

We have checked the ground, the fuse, everything we can possibly think of. Only thing we have to think now is that there is a loose wire for the fan.

 

[Fast69Mopar]

Hello All, This may be answered somewhere already so I apologize for another thread. My husband is having issues with his radiator fan not working.
2018 Ram 1500 3.6

He changed the fan, that wasn't the problem, he changed the thermostat and the coolant tempature sensor as well as the PCM. None of those are the problem. He's at a loss and so am I. My brother in law the mechanic can't even seem to know what the problem is.

Can someone please give us another idea to look for? We truly appreciate the help.

The first thing that should have happened is connecting a scan tool to verify that the PCM is commanding the electric cooling fan to come on or not. This would have saved you the cost of a new PCM.

With a proper scan tool that has bi-directional capabilities you can actuate the fan and test the wiring in the fan circuit.

A quick glance at the wiring diagram shows that Fuse #2 125A Battery Fuse and Fuse #1 80A B+ are red wires that supply battery voltage to the fan at all times and the black wire from the fan is grounded at the G104 ground on the left side of the engine compartment. Pin #4 in the fan connector is the fan speed sense signal that goes to the PCM. It is not a single wire (hardwired) to the PCM. It goes through a few connectors in the wiring harness.

Check for B+ battery voltage at the fan connector. Check for ground at the fan connector. If you do not have B+ battery voltage at the fan connector you will have to follow the wire through the harness and find out why it does not have voltage.

I have attached a PDF of the E-Fan Wiring Diagram.

 

[dsherman26]

Is the relay clicking on? Should be able to use a bidirectional scan tool to command the fan on and determine if the relay is being energized.

 

[genesiskt]

It doesn't have a relay. It only has the 80 amp fuse, which we switched out the entire fuse box with my brother in laws truck (same truck) and it works. As well took the entire fan out and hooked it up in his truck and it works. We are at a loss for this evening but will be hooking up a scan tool again tomorrow to see if that can help us trace the issue. My husband has the diagram that was sent as well and will be looking at that tomorrow. Thank you for all the responses. Hopefully we can figure it out soon.

 

[metalchewy]

Try getting the engine really hot and turn on the AC...

The fan bolted to the water pump is the radiator fan.

To get the electric condenser fan to run, I'd think it would need to be hot and have the AC on. If just running the heater it shouldn't be on.

 

[BenchTest]

Try getting the engine really hot and turn on the AC...

The fan bolted to the water pump is the radiator fan.

To get the electric condenser fan to run, I'd think it would need to be hot and have the AC on. If just running the heater it shouldn't be on.

The 3.6L uses an electric fan only. There is no fan bolted to the water pump. The stock fan on a stock truck should be cycling on at/near 225 degrees. The electric fan will only engage earlier if ambient temperature, climate control, and coolant temp requirements are met. It is a pulse width modulated fan (PWM) as well, not a traditional "on/off" 12VDC fan.

As stated before, the proper test for this would be commanding it on/off via scan tool.

 

[HarryS]

Check pin 2 on connector C2 on the TIPM. Red wire 8 gage. It should have power on it all the time the key is on. It goes directly to the fan, and the PCM supplies the ground to turn the fan on or off.

 

[genesiskt]

Thank you everyone. It was a bent pin from when he was adding something else for the push start that was added. You all are amazing with responding and we truly appreciate it.

 

[Fast69Mopar]

Thank you everyone. It was a bent pin from when he was adding something else for the push start that was added. You all are amazing with responding and we truly appreciate it.

Glad you guys were able to figure it out. Sucks you had to spend all of the extra time and money to get to the conclusion. Good job on finding the problem.

 

[truck2569]

Hello All, This may be answered somewhere already so I apologize for another thread. My husband is having issues with his radiator fan not working.
2018 Ram 1500 3.6

He changed the fan, that wasn't the problem, he changed the thermostat and the coolant tempature sensor as well as the PCM. None of those are the problem. He's at a loss and so am I. My brother in law the mechanic can't even seem to know what the problem is.

Can someone please give us another idea to look for? We truly appreciate the help.

Check the fuse mine use to go out on my 3500 Ram all the time.