HELP: Radiator Fan randomly Turns on..

[SicsDeep]

So I had some body work done on my car after my car came in contact with a deer. Previous to them working on my car, this problem did not occur.

The problem is the radiator fan will randomly turn on even with out the key in it or when it has a completely cold (28ºF) temperature. It seems to happen at about 20 min after the car has been running. I have unplugged the battery so it does not drain overnight.

Any idea what could cause this or anyone have any similar problems in the past? I am bringing it right back to the shop tomorrow first thing in the AM but want to know what could be wrong.

Thanks in advance.

 

[BAMF]

Maybe the relay that powers the fan is damaged? The ECU sends the signal to turn the fan on, sometimes even when the car is off (like when you park it after a hot run.) If it started happening after a front end collision, I'd check the relay as well as the power wires to the fan (could be that the wires are damaged and shorting.)

 

[SicsDeep]

Maybe the relay that powers the fan is damaged? The ECU sends the signal to turn the fan on, sometimes even when the car is off (like when you park it after a hot run.) If it started happening after a front end collision, I'd check the relay as well as the power wires to the fan (could be that the wires are damaged and shorting.)

After the collision it did not happen. The damage was almost all cosmetic and this problem did not occur from after the accident until I brought it to the body shop. So my guess is something happened in the body shop that may have been disconnected. The only radiator related part that was replaced was the radiator support. I am kinda stumped. But I will def have them check the relay.

 

[eurocars]

could be the coolant temp sensor went bad? If it was telling the ecu the car was hot the fans may come on sporadically

 

[The Fed]

The fans should only run for a short time after you shut the car off, and only when it's hot. The most mine run is 5 seconds or so during the Florida summers.

My guess is either the coolant sensor or wiring. I have no idea how to check the module in the large fan or if it can even be the problem. Usually when it goes you get no fan.