Radiator fans not turning on

Tiny
EMAGMIND
  • MEMBER
  • 2006 CHRYSLER PACIFICA
  • 3.5L
  • V6
  • FWD
  • AUTOMATIC
  • 130,000 MILES
I cannot get radiator fan to turn on automatically. I have replaced the coolant temperature sensor as well as the radiator fan relay. With the relay power supply cord, I have confirmed that pin 1 A112 gives a 12 volt reading. I have also confirmed that pin 2 N23 gounds and starts fans when supplied a direct 12v current. I cannot get pin 4 k173 to give a reading, even when I left the car on to overheating temperatures (which I was hoping the sensor was just waiting to send a signal). Although maybe I should not have, I applied 12 volts to pin 3 z723 and it popped electricity. When I put my meter on it though it seemed to be fine with the 12v reading. I have checked fuse 13 in the Power Distribution Center and have confirmed continuity. Additionally, I get a 12v reading from the positive. However, I cannot get a reading going to the ground.

Please help, I am losing my mind and I know nothing about any of this until I started googling yesterday.
Do you
have the same problem?
Yes
No
Monday, June 27th, 2016 AT 11:38 AM

4 Replies

Tiny
HMAC300
  • EXPERT
This system is not complicated here is the wiring diagrams and a guide to help you check the signal from the PCM.

https://www.2carpros.com/articles/how-to-check-wiring

Check out the cooling fan diagrams and PCM location (Below). Please let us know what happens.

Cheers
Was this
answer
helpful?
Yes
No
+3
Monday, June 27th, 2016 AT 12:14 PM
Tiny
EMAGMIND
  • MEMBER
I have the following codes:
P0420- Catalyst System Efficiency Below Threshold (Bank 1)
P0457- EVAP System Loose Fuel Cap
P0456- Evaporative Emissions System - Small leak detected
P0305- Cylinder #5 Misfire
P0480- cooling fan 1 control circuit malfunction

P480 would be the one indicating an issue here and I do not get a signal on the violet wire pin 4 with the relay power supply. I tried letting the car get hot too, to see if it was reliant on the temperature sensor. However, I got a used PCM for the car and plugged it in. The fan started working again all fixed thanks for your help on this. They tell me I got luck the PCM worked some need to be reprogrammed I guess.
Was this
answer
helpful?
Yes
No
+2
Monday, June 27th, 2016 AT 12:35 PM
Tiny
JIS001
  • EXPERT
You should start by having a compatible scanner to see if you can command the fan relay on and off. If commanding the relay on makes the fan come on then you know your circuit is okay. Have you checked to see if maybe your thermostat is stuck closed? If the coolant is not circulating the reading to the PCM will always be cool and not allow the fans to come on? Check your upper and lower radiator hoses to see if the lower is cooler then the upper hose when it starts to over heat. You could also have air in the system if the cooling system has being open?
Was this
answer
helpful?
Yes
No
+1
Monday, June 27th, 2016 AT 6:59 PM
Tiny
AHOFFE42
  • MEMBER
Thanks for this post. I had the same problem and the dealer charged me $550.00 to replace the PCM. I wish I found this post earlier.
Was this
answer
helpful?
Yes
No
Sunday, May 27th, 2018 AT 7:37 PM

Please login or register to post a reply.

Recommended Guides