SPONSORED LINKS

Where in the radiator fan is the control module located?

Tiny
NINELIVES IVES
  • MEMBER
  • 2016 DODGE GRAND CARAVAN
  • 3.6L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 145,000 MILES
Fan only runs when temperature sensor is unplugged. I am an electronic tech and may be able to repair module. If I can find it. Further info. I only have a cheap scanner. Fan and fuses all good. Relays in fuse box and the two by left headlight good. Traced all wires by color and verified live function of all relays. I found that the main fan relay did not have a change in control when a/c or sub relays switched. I checked fuses, relays, and fans both physically with meter and live. I just happened to see in a forum about the fan defaulting to on when signal lost from temperature sensor. I Unplugged -Bingo. One other thing. The outside temperature has been in the low 20's the past few days. Coolant temp shown in vehicle info screen on dash has been going to as low as 180 while driving and fluctuates with heat becoming less intense when coolant temp is low. Acts like thermostat sticking open. Just replaced thermostat - no change. No overheating. Fan is in-op for both cooling when coolant temp goes up and during a/c. Could faulty temp sensor readings but a culprit. I am capable of checking voltages if I had schematic and pinouts of PCM or fan control module.
Thank you in advance.
SPONSORED LINKS
Monday, December 2nd, 2024 AT 7:57 PM

9 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,345 POSTS
Everything sounds normal from what you have described except the fan not coming on when the A/C is on, But I need to add you may need to leave the A/C on for a while in this cold weather to get the high side pressure switch to trigger. Are you having any other issues besides that? Here are the radiator cooling fan wiring diagrams so you can see how the system works also, the fan control module is on the fan shroud, they call it a resistor FYI. Check out the images (below). Please let us know what happens.
Images (Click to make bigger)
Thumb
Thumb
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Tuesday, December 3rd, 2024 AT 10:59 AM
Tiny
NINELIVES IVES
  • MEMBER
  • 6 POSTS
Thankyou Ken, just what I needed. Bought 2 months ago with issues. Over heating - changed out oil cooler leaking both oil and water. Fans never came on. A/C works fine fan never came on. I was able to trace and figure out last night that low speed B+ is supplied by relay k11 in the TIPM (which I see is being triggered by a separate circuit board built into the TIPM - relaying the engage data from the PCM) and high speed is supplied by the large relay under the left head light (being fed by the PCM relaying the engage from data lines. Am I correct in assuming that unplugging the Coolant temperature sensor is engaging the fan through default mode? I haven't checked which relay is feeding the fan, but I am assuming it's high speed (having never heard the fan before). Both HVACs are charged properly and operate properly, just no fan. This kind of leads me to the PCM and my ignorance does not know where the data lines come from. Is this from the PCM? Since both low and high are not being activated the common thread is the PCM or wiring from the PCM? Your input is greatly appreciated. Your schematic is much more complete than the one I made and very helpful. If you have further input, I'm sure it would be helpful and time saving. Any common culprits in this scenario that you know of?
With appreciation,
Tom I
Was this
answer
helpful?
Yes
No
Tuesday, December 3rd, 2024 AT 5:05 PM
Tiny
NINELIVES IVES
  • MEMBER
  • 6 POSTS
I'm going to hold off on pulling the TIPM apart to find whatever circuit is buried in there as I do believe it is something affecting signal from data to both the TIPM and the large relay.
Was this
answer
helpful?
Yes
No
Tuesday, December 3rd, 2024 AT 5:08 PM
Tiny
NINELIVES IVES
  • MEMBER
  • 6 POSTS
I answered all my questions by studying the schematic. Next step I'm going to pull the c1 connector on the PCM, where I think the issue is. Second step if not there, trace wires to TIPM check that connector. I'll let you know what I find. Might be a few days before I can get back to it. Thanks again.
Tom I.
Was this
answer
helpful?
Yes
No
Tuesday, December 3rd, 2024 AT 6:19 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,345 POSTS
No problem, I can tell you the TIPM have had issues in these cars, but it is easy to replace because it-self learns. Let me know what you find when you get the chance.
SPONSORED LINKS
Was this
answer
helpful?
Yes
No
Wednesday, December 4th, 2024 AT 10:08 AM
Tiny
NINELIVES IVES
  • MEMBER
  • 6 POSTS
Cleaned connectors on PCM. Did following tests. Grounded k11 in TIPM - low speed fan engaged. Grounded High speed relay with engagement. Replaced ECT with plug and let ECT hang and heated up with lighter. High speed fan responded @ 234 degrees. I looked up ECT resistance/temp chart and found measured resistance to be considerably high. Current ECT is aftermarket. Will replace with OEM. There are three wires on the high-pressure HVAC sensor. Is there a way to jumper/disconnect to get PCM to turn on fan? Does the high-pressure switch trigger the low-speed fan?
Was this
answer
helpful?
Yes
No
Wednesday, December 4th, 2024 AT 4:07 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,345 POSTS
I would not mess with the AC pressure switch, there is a 5-volt reference and two sensor and compressor wires, you might be able to jump them, but you might blow out the TIPM as well. Check the wiring diagrams below.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Thursday, December 5th, 2024 AT 1:15 PM
Tiny
NINELIVES IVES
  • MEMBER
  • 6 POSTS
I'm all set. Thank you for your work. Is there some way I can make a contribution to what you do?
Tom I
Was this
answer
helpful?
Yes
No
Friday, December 6th, 2024 AT 4:31 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 48,345 POSTS
That would be great, here are the links:

https://www.paypal.com/ncp/payment/VTBAJSABCQ2CN

or

https://gofund.me/c7d318ad

Thanks again! :)
Was this
answer
helpful?
Yes
No
Saturday, December 7th, 2024 AT 12:21 PM

Please login or register to post a reply.

Sponsored links