RADIATOR FANS STAY ON

[Jacobwade]

I have a 2014 Silverado 6.2 liter. Left one morning and temp

gauge was not moving and fan was running on high, it was only 48 degrees outside. Fan continued to run after truck was turned off and keys were out of ignition. Read through this forum and watched multiple videos. Replaced thermostat and coolant temp sensor for about $80.00 in parts. But buy a jug of replacement coolant cuz it will spill a lot doing repair. Fixed the issue so far. 

[richard wysong]

Welcome to the Forum Jacob!

[5RWill]

Anyone had this issue with the coolant sensor then coincidentally have their fuel gauge also start to act faulty? 

[Rusty Shackleford]

Yep, just went thru this too. Coolant temp sensor and t-stat replaced. Cleared the code, and problem solved.

[Randomdude951]

My 2014 Sierra 5.3L had this exact issue. I changed the thermostat and temp sensor to no avail. Nothing would fix the fans running and it even started causing my alternator to have low voltage, and the temp sensor wouldn’t work despite being new. I ended up disconnecting the negative terminal and let it reset the computer. After doing the reset everything works as it should, if not better than it has in a long time. If you’re having this issue I recommend giving this method a shot.

Edited December 19, 2024 by Randomdude951

[Jonfloyd]

2014 Silverado 5.3LT 

multiple time engine fan runs at full speed even after the vehicle is shut off. It will not allow the engine to warm up, its subzero winter in Michigan. I disconnected the battery and replaced coolant temp sensor.  Via YouTube troubleshooting. This seems to work for a week or so. Took to a master mechanic he replaced a sensor under the thermostat and the thermostat. That worked for a year. Now it’s doing it again and so cold out side the fan running on high doesn’t allow the engine to warm up. 
I replaced the coolant temperature sensor again and it worked for a week. Fans back on today. 
*ether disconnecting the battery resets the computer and It matters not that I changed the coolant temperature sensor again. 
*could it be a faulty relay issue? 
going crazy with this thing. 
 

[richard wysong]

Probably the thermostat again, the fans won't stop the engine from warming up if the Tstat is working properly

[BIGDOGx]

On 1/30/2026 at 8:43 AM, Jonfloyd said:

2014 Silverado 5.3LT 

multiple time engine fan runs at full speed even after the vehicle is shut off. It will not allow the engine to warm up, its subzero winter in Michigan. I disconnected the battery and replaced coolant temp sensor.  Via YouTube troubleshooting. This seems to work for a week or so. Took to a master mechanic he replaced a sensor under the thermostat and the thermostat. That worked for a year. Now it’s doing it again and so cold out side the fan running on high doesn’t allow the engine to warm up. 
I replaced the coolant temperature sensor again and it worked for a week. Fans back on today. 
*ether disconnecting the battery resets the computer and It matters not that I changed the coolant temperature sensor again. 
*could it be a faulty relay issue? 
going crazy with this thing. 
 

Did you replace the t-stat with a AutoZone China special part or a factory AC/Delco brand?

[mikeyk101]

2 hours ago, BIGDOGx said:

Did you replace the t-stat with a AutoZone China special part or a factory AC/Delco brand?

Good point. My original thermostat went bad and was getting stuck open after it was about 7 years old. I replaced it with a Motorrad and within a couple months, that one was getting stuck either closed or partially closed. I changed that out for an AC Delco which has been working fine ever since. The first one lasted over 7 years so I should have just gone back to OEM in the first place because of reliability.

[BIGDOGx]

1 hour ago, mikeyk101 said:

Good point. My original thermostat went bad and was getting stuck open after it was about 7 years old. I replaced it with a Motorrad and within a couple months, that one was getting stuck either closed or partially closed. I changed that out for an AC Delco which has been working fine ever since. The first one lasted over 7 years so I should have just gone back to OEM in the first place because of reliability.

It is bad right now, look on Youtube and you literally have auto techs questioning if they want to continue being a mechanic because of how bad the quality is with Auto parts today. For anything that is a sensor or an engine related piece i would stick with OEM only, you will never save in the long run no matter how much cheaper that generic brand part is.

[mikeyk101]

1 hour ago, BIGDOGx said:

It is bad right now, look on Youtube and you literally have auto techs questioning if they want to continue being a mechanic because of how bad the quality is with Auto parts today. For anything that is a sensor or an engine related piece i would stick with OEM only, you will never save in the long run no matter how much cheaper that generic brand part is.

 

I would add brake pads on to the lists as well. A couple years back when front brakes needed to be replaced, I bought "quality" aftermarket brake pads from the local store. They ended up being a bit too wide and wouldn't move freely in the caliper bracket and would bind against the rotor upon braking. I saw mention of shaving some metal off the ears but why should I?  I returned those, went with OEM, and they fit right the first time. 

[Taymara666]

On 1/27/2021 at 2:44 PM, MrMiller said:

I was having the same issue with the cooling fans being on full speed when turning off the vehicle.  The temp gauge was pegged at the bottom at 160°F.  I would have to disconnect battery to turn them off.  This only happened intermittently with no clear reason for it happening.  Dealer found a "stuck open" Thermostat and changed it out which they say is the reason for the fan staying on after turning the vehicle off.  This was just today 1-27-2021.  We will see if this takes care of the issue and I will update later...

Update???

[davester]

...just fyi, that was a 5 year old post, and that user just made that single post and never returned to the site since then.  You aren't going to get a response from that user.