Cooling fans will not turn on

Tiny
CBRASSO
  • MEMBER
  • 1996 TOYOTA CAMRY
  • 2.2L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 160,000 MILES
Okay guys, here’s the breakdown: Cooling fans won’t come on causing car to overheat. Fans will run with AC on. Now I unplugged the wire from the sensor on the bottom of the radiator and both fans come on. I replaced the two sensors going into the block one is a sensor the other a sender I believe? Still having same issue. I did check voltage out of those wires and do have voltage. My question is, could the sensor on the radiator be bad or is it something else? Stumped. Now I have power to the 2 going in the motor but not sure how much there should be. One of them is a single pin connector.
Sunday, August 4th, 2019 AT 11:13 AM

40 Replies

Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Good afternoon,

The coolant sensor that controls the fans is on top of the motor at the distributor. I attached a picture for you to view. Check that sensor.

https://www.2carpros.com/articles/engine-overheating-or-running-hot

I am worried from the overheating that you may have damaged the head gasket.

https://www.2carpros.com/articles/head-gasket-blown-test

Roy
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Sunday, August 4th, 2019 AT 1:48 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
ASEMASTER6371 the one near the distributor are the ones I changed. I have no water in oil no bubbles in radiator do I need to continue with the compression test and so forth? And would changing switch on radiator help?
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Monday, August 5th, 2019 AT 10:47 AM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
You could try changing the switch, yes.

Yes, I would still do the test for the head gasket.

Did you check for voltage at the sensor and the switch at the radiator?

Roy
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Monday, August 5th, 2019 AT 10:50 AM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
No sir, only the sensor but will check the switch. Any idea what the voltage should be? And okay, I’ll do the head gasket test. Thanks, I’ll report back.
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Monday, August 5th, 2019 AT 7:09 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
Sensor should have 5 volts.

Switches have 12.

You are welcome.

Roy
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Monday, August 5th, 2019 AT 7:28 PM
Tiny
CBRASSO
  • MEMBER
  • 43 POSTS
I got it ! Fans are kicking on with the switch plugged into the radiator. I really appreciate the help! Btw. There was no voltage at the switch. One wire cut about a foot from it. Thanks again guys!
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Wednesday, August 7th, 2019 AT 4:59 PM
Tiny
ASEMASTER6371
  • MECHANIC
  • 52,796 POSTS
You are welcome.

Always glad to help.

Roy
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Wednesday, August 7th, 2019 AT 6:15 PM
Tiny
JAVARAE
  • MEMBER
  • 1 POST
  • 1996 TOYOTA CAMRY
Four cylinder four wheel drive automatic 130, 00 miles.

Coolant fans not working, both fans do work if air is turned on. Does this point to any particular fix for coolant fans not working? I do not know which fuse or where they are located, for coolant fans. I see fan number one is first fuse/relay box closest to battery, and in next fuse/relay box fans two, three and air relays. Do not know which are fuses and which are relays? Would truly appreciate any help. Not familiar with auto repair but am trying. Thank you.
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
DSPLC
  • MECHANIC
  • 220 POSTS
Below is the relay. It is a small box type.


https://www.2carpros.com/forum/automotive_pictures/89255_fan_relay_1.gif



Below are fuses. There should be number markings on the top like 5A or 5, 10A or 10, and so forth. Replace only with the same number. (5A as "A" stands for amperes)


https://www.2carpros.com/forum/automotive_pictures/89255_fuses_1.jpg



Suggestion: Try checking the ECT (Engine coolant temperature) switch for electric cooling fan located at the bottom of the radiator. (either left or right side). With the engine OFF, unhook the wire connected to the ECT switch. Now turn ON the engine, if the fan runs, then maybe it is the ECT switch. You need a new one pictured at the bottom with the O rubber ring.


https://www.2carpros.com/forum/automotive_pictures/89255_ect_switch_1.jpg



https://www.2carpros.com/forum/automotive_pictures/89255_ect_sensor_1.jpg

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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
TYLERBDAD
  • MEMBER
  • 1 POST
  • 1996 TOYOTA CAMRY
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 140,000 MILES
Car started overheating changed the thermostat and radiator.I noticed that the cooling fans were not coming on.Wife says she noticed it about the time car started to overheat.Both motors on fans work I made jumper to battery.Changed 30 amp fuse links and 1 relay inbox beside battery. Both fans work when air is on now but radiator fan doesn't come on by it's self when you start car with air off.


http://www.2carpros.com/forum/automotive_pictures/173611_girl_apply_mascara_1.jpg


Note round silver fan motor relays in fuse block seem to be very warm at times
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
MIKE H R
  • MECHANIC
  • 3,094 POSTS
When you turn the ac on the fans are suppose to run as well when you put the window defroster. The rest of the time the are off until the temperature reaches a certain temperature. You should have two fans. The problem could be in the temperature sending unit for the fans. With the fans running check to see if one or both are making a noise to see if one or both motors could be going bad.
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
MARK KENNETH SMITH
  • MEMBER
  • 1 POST
  • 1995 TOYOTA CAMRY
  • 4 CYL
  • 2WD
  • 125,000 MILES
1995 toyota camray. 4cyl. The radiator fan doesnt work. Had to replace new radiator but fan will not work.
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Probable causes here could be the fan motor, fan relay, engine temperature sensor/gauge switch and computer-
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
DRCRANKNWRENCH
  • MECHANIC
  • 3,380 POSTS
More than likely the fan relay is bad. It should be located near the fan. If you follow the electrical leads from the fan, they will lead to the relay. They are generally around $20-$40 and are a simple clip in and maybe a bolt to reatin it for replacement.
Let me know if that helps.
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
KEVAUG
  • MEMBER
  • 3 POSTS
  • 1995 TOYOTA CAMRY
  • 4 CYL
  • FWD
  • MANUAL
  • 242,000 MILES
I have a 95 Toyota Camry - 4 cyl DX. The radiator cooling fans are not coming on. I flushed the radiator and tested the fan switch and it is working fine. It opens up at about 205 degrees. The coolant sensor is also good - it read about 3500 ohms at about 45 degrees (cold car). I also tested the 2 relays associated with the fans (the main and fan 1). They were also good. As the temp increases I can disconnect (essentially open up) the fan switch wire and the fans will run. Also if I leave the switch wire disconnected the fans run when I start the car as well. But once I hook up the wire from the fan switch to the control it does not come on (essentially a short). Any help would be appreciated. Thanks Kevin
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
FISHERMAN
  • MECHANIC
  • 937 POSTS
Hello !

The cooling system on these cars is a little complicated, they use a micro-computer to controll the fans, also there is a pressure switch on the a/c line that controlls the fans also, but, if you disconnect the temperature switch and the fan works that means that your problem its the thermoswitch, check it good, it should be "open" when hot and closed when cold.

Good luck!
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
KEVAUG
  • MEMBER
  • 3 POSTS
I drained the radiator, pulled the thermo switch and paced it in a pot of water on my gas stove.
I took my ohmmeter and saw that it was closed up to about 200 to 205 degrees at which time it did "open" up.

I dont think its the thermostat because as the car warms up from cold I can see the thermostat kick in.
I can drive the car about 25 minutes before it starts to overheat.
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
FISHERMAN
  • MECHANIC
  • 937 POSTS
Ok, if you disconect the wire from the thermoswitch and the fan turns on that means the switch its not "sensing" the temperature, everything else its working the way its supposed to.

Did you "purged" the air out of the system?

I mean, it could be a pocket of air in the system and the thermoswitch didnt work with hot air, it needs "hot water' to open.

Disconect the top radiator hose (from the radiator) and pour on it "hot water" to open the thermostat and let the air out of the engine.

I`m sorry if I insist but I really think that the problem its there.

Let me know!
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
KEVAUG
  • MEMBER
  • 3 POSTS
Hi - I disconnected the upper hose and poured boiling water into it. It filled the hose and then
when down a bit (I assume because the thermostat opened up).
I have never replaced the thermostat. I know when it warms up the temp gauge rises and then levels off in the middle so I just assumed it worked.
Maybe I should just replace it. Is there an easy way to test it or is the hot water trick enough.
If so could it possibly be my water pump?
I dont see any leaks but maybe the impellar is broken
or free spinning?
Thanks for all the ideas
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Monday, January 25th, 2021 AT 12:41 PM (Merged)
Tiny
JRS DAD
  • MEMBER
  • 2 POSTS
  • 1994 TOYOTA CAMRY
  • 1.1L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 140,000 MILES
Coolant is lost, top of radiator is hot but coils are still cool. Removed hoses and blew air through radiator passes okay so does not seem blocked.
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Monday, January 25th, 2021 AT 12:41 PM (Merged)

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