Mechanics

TOYOTA RAV4 RADIATOR PROBLEM

1997 Toyota Rav4 • 142,000 miles

Radiator fan isn't working the way it's supposed to. I dismantled the compressor, the condenser, and the a\c lines. I replaced the alternator belt with a new shorter belt, and car starts and runs. I saved the electrical connector of the R-134 bottle because: When this connector is unplugged from the circuit, the radiator fan, and the condenser fan turn on and stay on when engine is started. But when this R-134 connector is unplugged from the circuit, the fan(s) never turn on. My next step: I took out the fan #3 relay ( this relay is definitely required if the a\c system is to be functioning), and nothing changed. I have a hunch that a jumper wire somewhere at the relay box may be all that's needed to remedy the problem. Thanks for your help. If it makes it easier for you to give me instructions, I have access to Alldata. Com for the rav4.
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Georgeomar
March 27, 2013.




The fan control for cooling system is controlled by the sensor in the bottom of the radiator.

Removing the ac components will not effect the operation of the cooling fan

Roy


ASEMaster6371
Mar 27, 2013.
You must be saying the ECT switch or sensor? That crossed my mind. But the R134 bottle electrical plug would still have to be connected to rest of circuit ( even if seperated from the bottle (which is my situation)) to keep the fans from being on continually. Are you saying to keep that in the circuit, but replacing the ECT switch would turn fans when temperature reaches 93•Celsius?


Tiny
Georgeomar
Mar 27, 2013.
The switch would operate the fans when temp is needed.

Why dont you just remove the switches from the ac lines and plug them in and tie them off

Roy
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ASEMaster6371
Mar 27, 2013.
You need to use a jumper across the A/C pressure switch terminals for the system to work correctly.


KHLow2008
Mar 27, 2013.
Could I access the A/C pressure switch from the big ekectrical plug that used to connect to the compressor?


Tiny
Georgeomar
Mar 27, 2013.
To KHLow2008
I'm not near my car now, but I think I know where the A/C pressure switch is: It's, if I'm not mistaken, accessible from the electrical connector that connects to the R-134 bottle. I'll verify when I get home


Tiny
Georgeomar
Mar 27, 2013.
Good morning,
I put a jumper wire across 2 terminals in place of the R134 bottle, this would bypass the A/C pressure switch if I read the schematic correctly: the bypass stops the fans from being turned on continually. But the fans never turn on as well. Does that mean the ECT sensor went bad. ECT sensor is supposed to make fan turn on when temperature reaches 93celcius?


Tiny
Georgeomar
Mar 28, 2013.
Not the ECT. It is the A/C water temperature switch, item # 12 in diagram.

The fan comes on only when the coolant in radiator is hot ehough to turn it on. When starting from cold, it might take between 20 to 45 minutes before the fan starts working, depending on weather?

Is the engine overheating while the fans are not working?


KHLow2008
Mar 28, 2013.
My mistake. But that's the part I was referring to. It's located at the bottom of radiator, next to the lower radiator hose. Is this part still working? Can it be tested? The reason I thought, either the a/c water temperature switch went bad or the circuit requires another bypass, was because the fan used to turn on when the RPM was raised at idle ( before dismantling a/c components).


Tiny
Georgeomar
Mar 28, 2013.
The engine is not overheating. ( I forgot to answer you Q. In my previous post).


Tiny
Georgeomar
Mar 28, 2013.

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