One radiator fan runs, the other does not


JoshBarber
04-17-2006, 09:07 AM
94 Hyundai Elantra

When engine heats up, passenger side cooling fan kicks on....drivers side never shows sign of life.

Is this a common issue?
Is there a seperate sensor for each cooling fan? Or is it more likely the fan motor went, or theres an electrical short somewhere to it?

thanks

Bear
04-17-2006, 01:28 PM
If I recall correctly they are ganged to gether and there is one relay (for both overheat and AC). If you have AC, turn it on and see if both fans work, if not I would be looking for power to the fan that is inoperative (connection,short, or a bad motor).

JoshBarber
04-18-2006, 08:47 AM
If I recall correctly they are ganged to gether and there is one relay (for both overheat and AC). If you have AC, turn it on and see if both fans work, if not I would be looking for power to the fan that is inoperative (connection,short, or a bad motor).

Ive determined the fan itself is fine. Theres a short somewhere. Ive noticed theres a radiator HI and radiator LOW relay in the fuse box. Could someone tell me if one operates one fan, and one operates the other?

Huge favor -
If anyone could pull each of them one at a time when both fans are running, and tell me if either of them shut off, it'd be greatly appreciated. Theres no way to really check to see if these relays are good or not without replacing it.

Could someone tell me what the each relay is for?

Bear
04-18-2006, 10:03 AM
Ok so fan motors are fine. Here is my best guess (not having a wiring diagram available). The coolant temperature sensor send a signal to PCM to activate the fan realy (one relay for AC and Heat). Based on the temperature that the sensor sees the fans run at a low speed until that is not suffucient to keep the temperature down and then they go to high speed. Example, my 1988 BMW 750 has a two temperature switch in the radiator that wires to the fan relay. The temperatures are about 195 degrees "F" and 210 degrees "F" for high and low speed operation.

Hope this helps.

JoshBarber
04-18-2006, 10:33 AM
Ok so fan motors are fine. Here is my best guess (not having a wiring diagram available). The coolant temperature sensor send a signal to PCM to activate the fan realy (one relay for AC and Heat). Based on the temperature that the sensor sees the fans run at a low speed until that is not suffucient to keep the temperature down and then they go to high speed. Example, my 1988 BMW 750 has a two temperature switch in the radiator that wires to the fan relay. The temperatures are about 195 degrees "F" and 210 degrees "F" for high and low speed operation.

Hope this helps.


Could someone please pull each of the two relays under the hood labeled RAD HIGH and RAD LOW, while fans are running, and see what each shuts off?

JoshBarber
04-19-2006, 11:02 AM
WOW.

This Hyundai forum SUCKS! Little to NO activity!


For those that are interested in this thread.......even though I received very little help (Im use to the AutomotiveForum for Chevys which has constant helpful responses), after reviewing a wiring diagram..

The drivers side fan is to run for the A/C.

Passenger side radiator fan is for cooling under normal circumstances.

I assume in an overheating circumstance, both sides will run, but thats just an educated guess.

Bear
04-19-2006, 11:16 AM
You are correct that both fans run under exteme conditions. Except for AC,the fans are temperature controlled by coolant temperature sensor. Prior to 2001 the coolant gauge sensor was a separate item (screwed into the head just foreward of the thermostat housing) and the ENGINE temperature coolant sensor (controls the fans) was in the same spot just behind and closer to the thermostat housing. I just replaced the engine coolant tmperature sensor on my grandson's 2001 Elantra and it was crazy trying to find the correct part (one three wire sensor versus two separate sensors).

twospirits
04-19-2006, 08:31 PM
WOW.

This Hyundai forum SUCKS! Little to NO activity!Like it says in my sig, the more the members are involved the better we will be a community of automotive enthusiasts.

If you have suggestions or better yet have topics that will stimulate more conversation by all means pm me or post them up.

TS out

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