Electric fan alway running

do your car have air conditioning that's the only thing it can be.

Is it possible you did not get it adjusted correctly ?

The resistor pack is almost always close to the blower. It needs air moving across it to keep it cool. It is usually installed into the duct with two small screws. It has a connector with about 5 -6 wires, and is about 3/4 inch wide, and about 3-4 inches long. Some can be a little difficult to get out due to clearance, and their shape.

Also, it could be the fan speed switch that's giving you problems.

I had a similar problem. Is your temperature gauge pegged to the right as very hot? Or reads always cold, even when hot. If it is a 3100 motor their is a coolant temperature gauge sending unit under the air breather intake that is right next to where you replace the thermostat.

Get a haynes repair manual at a parts dealer, Amazon, or your public library.
On the Chevrolet Lumina, Monte Carlo, & Impala FWD 1995 to 2005 it's under section 3-8 on page 3-6. It goes into great detail, and it's too complicated to explain here. If your sensor is bad, but the wires and fuses are good then the fans won't run.

Your second fan only runs when the air compressor is turning, If your ac compressor is not running then the sensor will not have the passenger fan run.
You have to see if the fan motors are good and then the wiring is good, and no fuses blown. You might blow fuses so have extra blue ones if I remember right. Recheck fuses after testing.

does the vehicle have theft lock on it? i had a fam. member this week go three days without his vehicle that ran awesome too. using the same key he always did and all... i went and looked at his vehicle, noticed the theft light would come on when i put the key in the ignition, so i asked him about the key, and he said thats the one he always used, so i had him get me the original key for the vehicle, ( the one he was using he had made, and put the original up) he got it for me i put it in the ignition and the vehicle started right up.... there is a code in the key that the vehicle reads and if its not there the vehicle will not start.. Like i said he had used his key he had made, the whole time he has owned the vehicle, and it just now decided to do it.. dont know why... but hey its a thought.. hope this helps

Thanks, I found the answer on other sites.

go to toyota buy a fan belt, i think u can see a belt adjuster need the belt and engine , you just need to adjust the belt to very good tension

1. REMOVE GLOVE COMPARTMENT DOOR

2. REMOVE ENGINE (and ECT) ECU
(a) Disconnect the wire harness clamps.
(b) Disconnect the connectors.
(c) Remove the 2 bolts and engine (and ECT) ECU.
3. Two way flow heater models only:
REMOVE AIR DUCT (Motor cover)
(a) Disconnect the control link.
(b) Disconnect the connector clamps.
(c) Remove the screw.
(d) Release the claw and remove the air duct.
4. REMOVE BLOWER RESISTOR
(a) Disconnect the connector.
(b) Remove the 2 screws and blower resistor.
5. INSPECT BLOWER RESISTOR RESISTANCE
Tester connection Condition Specified condition
1 − 3 Constant Approx. 0.4 ω
1 − 2 Constant Approx. 1.5 ω
1 − 4 Constant Approx. 2.8 ω
If resistance is not as specified, replace the blower resistor.
6. INSTALL BLOWER RESISTOR
7. Two way flow heater models only:
INSTALL AIR DUCT
8. INSTALL ENGINE (and ECT) ECU
9. INSTALL GLOVE COMPARTMENT DOOR

Check the fan relay, probably in fuse box in the engine compartment. Check owners manual to be sure. I have seen these melt causing fan to run all the time.

http://www.carspace.com/guides/Changing-Cabin-Filter-on-Toyota-RAV4-Echo-Scion-xA-and-Scion-xB