Rad fans wont turn off

[JSeely]

So ive read many posts on this and i cant find one with a clear answer.

I was checking my air filter and it was fine so i closed it up and turned the truck on and the rad fans kicked on max and now it doesn't stop. the truck can be cold (50 degrees out) and it will kick the fans on max also goes for when its cold and 80 out. The temp gauge sits at 160 (low) and the ac and the heat dont really work. but then sometimes i can go a few days with out it happening. I've tried disconnecting the battery and waiting an hour but that only seems to help for a couple days (also could just be a coincidence). I don't know if it actually had to do with me opening the airbox but it seemed to start after i did that.

2014 Silverado 1500

[rlcole321]

3 hours min on batt disconnect to clear memory, why doesn't the AC work?, a faulty AC high pressure switch could be the cause, "fooling" the VCM into high Freon pressure, turning on fans and disabling the compressor.

[Dog840]

On 9/18/2021 at 11:52 AM, JSeely said:

So ive read many posts on this and i cant find one with a clear answer.

I was checking my air filter and it was fine so i closed it up and turned the truck on and the rad fans kicked on max and now it doesn't stop. the truck can be cold (50 degrees out) and it will kick the fans on max also goes for when its cold and 80 out. The temp gauge sits at 160 (low) and the ac and the heat dont really work. but then sometimes i can go a few days with out it happening. I've tried disconnecting the battery and waiting an hour but that only seems to help for a couple days (also could just be a coincidence). I don't know if it actually had to do with me opening the airbox but it seemed to start after i did that.

2014 Silverado 1500

 

Had a similar issue. Took the battery off for a few hours, replugged it in…after 500 miles, the fans started to be annoying again.

 

The fix for me was replacing the engine thermostat. I was in complete denial that it was the thermostat…but it definitely was the issue! 

 

(Also have a 2014, 5.3) 

[cooter32]

Finally an answer!!!!!! I've been searching forums and google with no clear cut answer.  To recap, the cooling fans are running at top speed even with the keys removed, the AC does not work and the temperature stays buried at 160.  It is either the thermostat stuck open or the temperature sensor has gone bad.  I replaced both and the problem was still there.  What every answer has failed to mention is that after the repair you must connect a code reader and reset the engine codes.  Not even the dealership could help me. Also I did not even have a check engine light during this issue but the code reader did show a P0128 code which is related to engine temp sensor or thermostat.

[huntster21]

So I just started having this issue a couple days ago it started out of no where. It doesn't start till I hit the gas and when that happens the radiator fans run full blast and it stays that way after a few minutes after I shut my truck off. I changed the coolant temp sensor yesterday thinking that was the issue from reading other people having the similar issue and it hasn't changed. I haven't changed the thermostat cause I haven't had an engine light on, but maybe that's why?

 

I have a 14' Sierra 1500 5.3

[pokismoki]

you either installed a low temp thermostat or the stock thermostat is failed open, this trips the fans to run 100% for saftety to protect from overheat.