Radiator fan not getting power

treblot · 09-15-2008, 08:57 AM

My daughters 2001 Rio ran hot. I found that the cooling fan is not working. I tested the fan and it is good. I checked the relay (#37) and it is good. Is there another fuse somewhere or a sensor that I should check? Thanks!

treblot · 09-15-2008, 09:29 AM

Can faulty thermostat cause no power to fan motor?

jcwit · 09-15-2008, 11:09 AM

How did you check the relay?

treblot · 09-15-2008, 12:05 PM

Thank you for responding. The steps below did pass so it seems to be good.

Continuity
85-86

Yes
87-30

No

[See large image...]
4.
If correct, go to next step.
5.
Apply 12V to the terminal 85 and ground the terminal 86.
6.
Check for continuity between terminals 87 and 30.
Terminals

Continuity
87-30

Yes

ron1004 · 09-15-2008, 12:34 PM

Quote:

Originally Posted by treblot

Can faulty thermostat cause no power to fan motor?

The thermostat controls the flow of coolant, so it's not the cause of of the fan not running.

The fan is controlled by a thermal switch - try find this and jumper it and check if the fan runs - if so then this thermal switch needs replacing.

Edit: I can't find the electrical schematics for the Rio, but it may be the latest control scheme which means the ECU monitors the temperature sensor and switches the fan relay as required - if it's this arrangement then lifting the wires of the sensor should make the fan run.

jcwit · 09-15-2008, 12:39 PM

Just for fun I'd try the relay anyway. I've had 3 that tested good with continuity but wouldn't keep working in the long run, replaced them and everything was good from then on. The ones that gave me fits were the horn, A/C, and dash tail lights. Tip, if you don't have dash lights when turning on the headlights you probably haven't got tail lights either. Good luck------------Try Ron1004 idea first, didn't think of that. dah

treblot · 09-15-2008, 12:50 PM

Thanks again. I jumped power to the fan and it runs. Where is the thermal switch located?

Here is the diagram, but I don't know how to read it.

http://www.kiatechinfo.com/data/manu...NG/rio015a.gif

ron1004 · 09-15-2008, 01:48 PM

Quote:

Originally Posted by treblot

Thanks again. I jumped power to the fan and it runs. Where is the thermal switch located?

Here is the diagram, but I don't know how to read it.

http://www.kiatechinfo.com/data/manu...NG/rio015a.gif

That's not the circuit diagram that we need.

See if you can find a more detailed diagram, and also check this temp sensor
http://www.kiatechinfo.com/data/manu...G/afjf381a.gif

ron1004 · 09-15-2008, 01:56 PM

I found the diagram for your car.

The ECU controls the cooling fan relay.

You can prove the relay, fan and wiring by placing a jumper on the diagnostics plug.

I've goto go out now so try find the DLC plug detail and jumper that - if the fan runs then there's a problem with the temperature sensor used by the ECU or the ECU it's self.

treblot · 09-15-2008, 02:55 PM

I am not sure what the DLC stands for, and have not been able to find it. I did find the sensor thanks to your diagram. I unplugged the sensor and started the car, after a few minutes the fan came on! So then I plugged the sensor back in and the fan continued to run. I stopped the engine and restarted it with the sensor plugged in and the fan is running now. Do you think it might have been a bad connection? Also the fan blade disintegrated where the teeth grab the motor shaft. I can't see anyway to fix that. Ihave to go out also but will check back tonight. Thank you very much for your help!