Cooling Fan Stopped Working
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
Cooling Fan Stopped Working
This morning I'm happily driving to work on the highway and I notice my AC is not blowing exceedingly cold so I start to look for problems. I watch my temp gauge steadily climbing. I have a 160' t-stat and my fans are programmed to come on early so I rarely see over 200'. It got up into the 230's and I pulled over. Not leaking coolant, hadn't thrown a belt, the fan fuse is intact. Hmmm. So I turn the ignition (but not motor) on and get out my laptop and use HPTuners to force the fans on. Nothing. I flash the tune to the car again because I have seen flaky stuff like this sometimes if a tune does not take 100%. I'm not too far from home so I wait a little bit and turn around and head home and notice that my temps are dropping and I can hear the fans. So I turn around and start heading to work again. About a mile from work temps start climbing again. The scanner shows the fan % at 90% but I don't hear anything. I was able to park before it got too hot but this is weird. I dont think it starting to work again had anything to do with the tune. I'm guessing either the fan controller or fan itself is going out (after 37k miles...
). So what is the more likely and how to test?
). So what is the more likely and how to test?
Last edited by 5 Liter Eater; Jul 10, 2009 at 10:12 AM.
Melting Slicks
Joined: Jul 2008
Posts: 2,014
Likes: 2
St. Jude Donor '09-'10
Dewitts >>> SPAL
A great time to add the SPAL fans which can be purchased through Dewitts. I would be interested to know the CFM's the STD 16" OEM fan puts out? They offer a several units including a hi-performance fan that puts out 2400 CFM. For some reason I beleive the GM model only puts out 2000 CFM. Maybe someone knows?
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
Like this one? http://www.dewitts.com/pages/product...asp?ProdID=240
Is that a common mod? Seems like you'd have to lose the shroud. Do you lose the fan controller too and just hard wire it to run full bore all the time?
Is that a common mod? Seems like you'd have to lose the shroud. Do you lose the fan controller too and just hard wire it to run full bore all the time?
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
What I found interesting is that I was cruising at ~50 MPH and that was not enough to keep the temps from rising... I guess the intercooler and removal of the front shroud have made the car dependent on the fan for airflow.
Last edited by 5 Liter Eater; Jul 10, 2009 at 11:40 AM.
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
In looking at sourcing the part(s) it doesn't look like you can just get the fan motor. You can get the controller separate ($154) or it's the whole fan assembly ($286) from GMPartsHouse. Local dealer wants the retail price of $439 and would need to order it anyway...
So if its the motor and I have to spend 3 bills I'm leaning towards an after market fan that would move more air. I wouldn't mind hard wiring an on/off non-pulsewidth modulated fan if it was A. cheaper and B. moved more air and C. is able to be mounted to the stock Z51 radiator without using those zip tie thingies that go through the radiator.
So if its the motor and I have to spend 3 bills I'm leaning towards an after market fan that would move more air. I wouldn't mind hard wiring an on/off non-pulsewidth modulated fan if it was A. cheaper and B. moved more air and C. is able to be mounted to the stock Z51 radiator without using those zip tie thingies that go through the radiator.
Melting Slicks
Joined: Jul 2008
Posts: 2,014
Likes: 2
St. Jude Donor '09-'10
Like this one? http://www.dewitts.com/pages/product...asp?ProdID=240
Is that a common mod? Seems like you'd have to lose the shroud. Do you lose the fan controller too and just hard wire it to run full bore all the time?
Is that a common mod? Seems like you'd have to lose the shroud. Do you lose the fan controller too and just hard wire it to run full bore all the time?
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
I donno. Right now I'm either going to get a new assembly through GM Parts House or make the $100 3000 CFM Zirgo fan I found work somehow.
Last edited by 5 Liter Eater; Jul 10, 2009 at 03:23 PM.
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Instructor
Joined: Sep 2006
Posts: 160
Likes: 2
From: Austin Texas
St. Jude Donor '08
possible solution
Had a similar problem, turned out the insides of the electrical connector for the fan, by the upper right side of the radiator, had melted--check the connector, seperate it and look inside.
intermittent failure, sounds like a loose connection, recheck the two plugs for the fan
Racer
Joined: Nov 2007
Posts: 292
Likes: 0
From: Orange County CA
Same problem I had and same solution. After I tested that the fan was ok by jumping a hot wire to it from a different power source and it worked fine, I then unplugged the connector on the wiring harness near the radiator and the center contact had melted causing intermittent short. I'd check that first.
Melting Slicks
Joined: Jul 2007
Posts: 3,097
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From: Brentwood World's first A6 in the 9's (including N/A, blower, turbo and nitrous cars) 9.950@139.267 CA
Melting Slicks
Joined: Mar 2008
Posts: 2,835
Likes: 5
From: Avon Park FLORIDA
St. Jude Donor '08-'09-'10
I had the same problem, the center pin in the controler plug turned black and not getting a good contact, I'll replace the plug and pins and make sure they are not loose causing resistance.
if you run your fan for a prolonged period at 100% they tend to do that, that's why GM has them limited to 90%.
if you run your fan for a prolonged period at 100% they tend to do that, that's why GM has them limited to 90%.
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
You guys were right. I disconnected the fan plug and immediately smelled burnt plastic. The plastic around the center pin of the connector was toast. I took the center pin out of both sides and connected it outside of the harness for now. See the carnage below.
Without you guys I would have bought a whole new fan assembly before finding this out. Thanks very much!
Without you guys I would have bought a whole new fan assembly before finding this out. Thanks very much!
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Holy cow Bill...
What are your fan settings? Here are mine.
192 196 199+
25% 75% 95%
I noticed if I had 192 over 25% the fan ran full on all the time.
Sheesh I see the stock settings don't hit 90% (the max setting) until 225 degrees!
I wonder if I should cut mine back.
What are your fan settings? Here are mine.
192 196 199+
25% 75% 95%
I noticed if I had 192 over 25% the fan ran full on all the time.
Sheesh I see the stock settings don't hit 90% (the max setting) until 225 degrees!
I wonder if I should cut mine back.
Melting Slicks
Joined: Mar 2008
Posts: 2,835
Likes: 5
From: Avon Park FLORIDA
St. Jude Donor '08-'09-'10
It burned up my new fan controler switch.
Missed you yesterday at HPS
Phil
Safety Car
Joined: Aug 2006
Posts: 4,347
Likes: 25
From: Apache Junction AZ
I had the same problem, the center pin in the controler plug turned black and not getting a good contact, I'll replace the plug and pins and make sure they are not loose causing resistance.
if you run your fan for a prolonged period at 100% they tend to do that, that's why GM has them limited to 90%.
if you run your fan for a prolonged period at 100% they tend to do that, that's why GM has them limited to 90%.
BJK
Thread Starter
Le Mans Master
Joined: Aug 2002
Posts: 8,472
Likes: 38
From: Houston TX
St. Jude Donor '11
I have the 2 bar OS which extends the fan table. So I WAS commanding 30% @ 174, 60% @ 180, 70% @ 185, 80% @ 190 and 90% from there on up.
I'm not convinced that the fan running more than normal would cause this. The rest of the connections were a-okay. I just think this is a design flaw in that connector. Even if it is a problem with running the fan that much there's not much I can do about it aside from replacing the fan with a higher flow one.
After realizing that I need the fan more than I thought because the blower setup doesn't provide good enough airflow to the radiator until higher speeds I've set the fans to 0% until 180' where I command 90% from there on up.
I'm not convinced that the fan running more than normal would cause this. The rest of the connections were a-okay. I just think this is a design flaw in that connector. Even if it is a problem with running the fan that much there's not much I can do about it aside from replacing the fan with a higher flow one.
After realizing that I need the fan more than I thought because the blower setup doesn't provide good enough airflow to the radiator until higher speeds I've set the fans to 0% until 180' where I command 90% from there on up.