Mechanics

RADIATOR FANS WONT TURN ON

1995 Toyota Camry

Engine problem
1995 Toyota Camry 4 cyl Front Wheel Drive Manual 242000 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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KEVAUG
February 11, 2008.



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!

Tiny
Fisherman
Feb 11, 2008.
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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Tiny
KEVAUG
Feb 11, 2008.
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!

Tiny
Fisherman
Feb 11, 2008.
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

Tiny
KEVAUG
Feb 12, 2008.

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