Chrysler Pacifica Luxury meets versatility in this mid-sized sport utility vehicle

Radiator Fans Not Running

  #1  
Old 12-08-2017, 03:38 PM
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Default Radiator Fans Not Running

Thanks for any help in advance.

I have a 2005 Chrysler Pacifica 3.8L that starts overheating when idling or driving at low speeds.

I have went through the circuits and found no issues from the 40 amp fuse to the fan relay, hot 12V.
I have tested the fan motors by bumping them with 12V from the battery, they work.
I have disconnected the ECTS and the fans kicked on, so I changed the ECTS.

Now the fans do not cut on with the rise in temperature or with the A/C cranked up.

What could be the problem ?

A/C pressure transducer or maybe the ambient temperature sensor ?
 
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Old 12-08-2017, 04:14 PM
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Update.

I should have said this in the initial post, the ECTS was changed last week Sunday and the vehicle has been driven to and from work all week.
Also the Over Temp light on the dash never comes on, so maybe overheating isn't the correct word.

I just drove the vehicle and the fans still haven't kicked on nor did they kick on when the A/C was cranked but it is 40* outside and raining so maybe the fans won't kick on with that being the ambient temperature.

Can anyone chime in on that assumption ?

Also I know when it is cold and raining and the motor is up to temperature that you may see steam coming off of the hood but I know the smoke I saw was coming from under the hood was from the grill and it was minimal,
nothing like when a vehicle is truly overheating.

Any information would be truly appreciated.
 
  #3  
Old 12-08-2017, 06:52 PM
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The fans only come on when needed as determined by the engine computer. In 40 weather they may not come on at all. If you're not overheating, you may not have a problem at all.
 
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Old 12-08-2017, 08:07 PM
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Originally Posted by dcotter0579 View Post
The fans only come on when needed as determined by the engine computer. In 40 weather they may not come on at all. If you're not overheating, you may not have a problem at all.
Thank you for the reply.

That may be but shouldn't the fans come on when the A/C is running regardless of ambient temperature ?

I may be paranoid but I don't want to be sitting on the side of the road either.

How do you feel about wiring the fans to a toggle switch bypassing the fan relay ?
 
  #5  
Old 12-09-2017, 07:15 AM
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Originally Posted by AshTre View Post
Thanks for any help in advance.

I have a 2005 Chrysler Pacifica 3.8L that starts overheating when idling or driving at low speeds.

I have went through the circuits and found no issues from the 40 amp fuse to the fan relay, hot 12V.
I have tested the fan motors by bumping them with 12V from the battery, they work.
I have disconnected the ECTS and the fans kicked on, so I changed the ECTS.

Now the fans do not cut on with the rise in temperature or with the A/C cranked up.

What could be the problem ?

A/C pressure transducer or maybe the ambient temperature sensor ?

Do you happen to have a Check Engine Light illuminated on the dash? You could do the venerated "Key Dance" and check for any code(s) for problems. My 04 T&C had a fan problem, and I got a code P0480. It turned out that there is a Radiator fan control module out in front of the radiator that went bad. I would not think that systems would change that drastically between models, and would be something to investigate.
 
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Old 12-09-2017, 10:02 AM
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Originally Posted by REBEL59 View Post
Do you happen to have a Check Engine Light illuminated on the dash? You could do the venerated "Key Dance" and check for any code(s) for problems. My 04 T&C had a fan problem, and I got a code P0480. It turned out that there is a Radiator fan control module out in front of the radiator that went bad. I would not think that systems would change that drastically between models, and would be something to investigate.
I didn't have the over temp light nor check engine light on but when I connected my scan tool to it it showed that same code.

So troubleshooting from the fans back to source I hit the relay and saw no power out of the relay to the fan but 12V from the 40 amp fuse in the relay box, so following the schematic saw that signal came from PCM from the ECTS.
So with the vehicle running and the fan relay connected unplugged the ECTS sensor and the fans fired off.

Relay is fine, so I changed the ECTS and the fans would kick on with the A/C and now they don't but like I said it could be the ambient temperature.
I do know once I unlugged the ECTS my scanner no longer shown fan relay circuit issues but temp sensor high and low codes. Now it shows nothing but I believe what I see with my own eyes.

I don't know, I don't even know if the fans will keep it from overheating even if I bypass the system and send 12V through a switch whenever I choose to.
 
  #7  
Old 12-09-2017, 10:40 AM
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There should be a rivet mounted module on the metal portion of front bumper ahead of the radiator(behind the grill). They have been known to go bad and also corroded/broken wire(s) near the modular connector. And I just looked up on google and yours has the same type part and system as my T&C. Easy to get to? I can not tell you on a Pacifica, but on my T&G I had to remove the Left headlight and disconnect the upper part of the plastic grill to access it. IMO patching into harnesses with makeshift switch controls is asking for trouble. But to conclude, the problem I had mimicked closely what you describe of yours. You could Google search yourself for yours with criteria for code P0480.
 
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Old 12-09-2017, 11:52 AM
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Originally Posted by REBEL59 View Post
There should be a rivet mounted module on the metal portion of front bumper ahead of the radiator(behind the grill). They have been known to go bad and also corroded/broken wire(s) near the modular connector. And I just looked up on google and yours has the same type part and system as my T&C. Easy to get to? I can not tell you on a Pacifica, but on my T&G I had to remove the Left headlight and disconnect the upper part of the plastic grill to access it. IMO patching into harnesses with makeshift switch controls is asking for trouble. But to conclude, the problem I had mimicked closely what you describe of yours. You could Google search yourself for yours with criteria for code P0480.
I know which part you are talking about, it is 4 wires and has 12V from the 40 amp fuse to energize via PWM from the PCM.
That is the relay I had left connected when I unplugged the ECTS connector and the fans kicked on which is how I know signal is getting back to the relay and energizing the fans.

P0480 is the fan relay circuit, it could be bad but I don't think it is, with the ECTS unplugged the PCM is pulsing the ground at 100% and the relay sends power out on the dark blue and dark green wire from the orange and red wire with 12V on it
from the fuse box.

I swapped out the ECTS because of that and because it was the cheaper part at $12.00 versus $30.00.
 
  #9  
Old 12-09-2017, 12:33 PM
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And you still have incorrectly working fans. BUT good luck in how you decide to proceed.
 
  #10  
Old 12-09-2017, 03:17 PM
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Originally Posted by REBEL59 View Post
And you still have incorrectly working fans. BUT good luck in how you decide to proceed.
I'm going to drive it until it warms back up again and then see what happens.

If it gets warmer when the cold front clears up and gets back up into the 60's I'll know if it is the ambient temperature or the relay.

If the fans kick on I may just change the relay anyway so I don't have to worry about it.

Thanks for your replies, I appreciate it.
 

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