Cooling fans

[ED.D.]

fans will not turn on unless ac is turned on. Only one fan was operational so I replaced the fans. Tested fans directly, old ones and the replacement, all good with both fans working. Still same problem so I replaced the thermostat, still fans only turn when ac is switched on. So then I replaced the coolant temp sensor, still fans only turn on when ac switch is turned on. Temp gauge does not
indicate higher than normal temp. I have nervously run the legacy to work while running the AC, did not over heat. I am stumped. need to go about 150mile trip and wondering if as long as temp gauge shows normal reading I can run it with ac turned on what the problem can be. Any help will be greatly appreciated as I am stumped. Thanks

 

[jasonrodgers1980]

Not sure about the legacy because im new to the platform, but with another car of mine (not a subaru), that's how it was meant to operate. Fans only come on if ac is switched on UNLESS overheating is present, then obviously fans kick on even if ac not on.

 

[ED.D.]

I was thinking fan should cycle on and off when idling or stop and go driving like my other vehicle. I initially checked fuses and relays by switching them around they seemed to have checked out. I just got back from auto parts where i was going to replace relay this time. They did not have it so I pressed the relay back in. I got back home and fan was running without the ac. Do not know if relay work intermittently on there way out so i am going to replace it and keep checking it

 

[bmart]

Have you checked the temp with a gun to see if they're acting properly?

 

[ED.D.]

Im mechanically inclined at best. How do you check temp with a gun

 

[bmart]

You'll have to research the temp at which one or both are supposed to come on (assuming two fans). Then use a temp gun like this (https://www.amazon.com/dp/B07GB7CDXS), near the sensor (you can check multiple places to ensure hot coolant is flowing everywhere) and see if it is coming on around the proper time.

 

[ED.D.]

You'll have to research the temp at which one or both are supposed to come on (assuming two fans). Then use a temp gun like this (https://www.amazon.com/dp/B07GB7CDXS), near the sensor (you can check multiple places to ensure hot coolant is flowing everywhere) and see if it is coming on around the proper time.

saw that the temp gun is only $16, I thought it would be expensive

 

[bmart]

And you can use it on your friends and neighbors...