Radiator fan not working

[Rweiss6]

Idled today for little while, gauge went close to overheating, fan did not go on. Once started driving, temp came down pretty quickly back to 190
How can I test fan ? I’ve searched forum but need basic info how to test to see if fan motor works , to start
Thank you !

[spider2081]

First: The ignition key does not need to be in any of the "on" positions for the fan to run. The coolant fan and the horn share fuse 10. Its the 10th fuse from the steering column. If your horn works the fuse for the coolant fan is good.
Next: I would check the coolant level in the over flow bottle. The coolant should be covering the top of the spike coming up from the bottom of the bottle.
Look at the engine side of the radiator, driver side bottom, this is where the fans switch is located. Follow the black sleeve up the wires to the 2 pin bullet connector. Unplug the bullet connector, make sure the contacts on both the switch's connector and the fans connector are clean Then using something like a short piece of wire jump the 2 pins in the cars (fan) connector. The one left when the fan switch's connector was unplugged. This should test (turn on) the fan.
Hope this helps

[Rweiss6]

Will do tmrw. Horn works. Not clear on instructions once I unplug connection and clean contacts.
What to do with short wire ? What to what ?
With key off, right ? Appreciate your help.

[spider2081]

What to do with short wire ? What to what ?

Use the short wire to connect the 2 pins in the cars connector together. This is the connector the switches connector was removed from. You could use something like a paper clip to momentarily connect the pins together.

With key off, right ? Appreciate your help.

Yes the ignition key does not have to be turned on.

[Rweiss6]

Coolant level was only bottom quarter of spike, added coolant to cover spike. Wondering - Is there a sensor in spike ?? Or in bottle ?

Disconnected fan switch, used wire to connect two contacts in wiring going to fan motor - nothing !!

Now what ? Anyway, unless I get stuck in traffic - thankfully rare- car runs at about 190 or less.
But I’d like to get this sorted out , part of the fun I suppose. Thank you

[spider2081]

The fan itself has it's own 2 pin connector with one wire being light blue the other wire is black I would unplug that connector and clean the pins on both mating plugs. That being the fans plug and the plug it plugs into. Both of the 2 pin connectors will have one light blue wire and one black wire. The motor needs a power wire and a ground wire to operate.
Do you have a volt meter or troubleshooting test light?

[ORFORD2004]

Short the switch and check voltage at the connector of the fan.
No voltage: Check the positive and ground to the body. Voltage present, you know that the problem come from the ground side. No voltage and you know that the problem is on the positive side.
Positive is always present and it's the ground that control the fan.

[Rweiss6]

Fan works ! I had unplugged wrong connection, one near top of radiator, it has no power to it.
Now I reached further down and found plug much closer to switch, disconnected then wired contacts together and fan started right up, seperate question -does it need lubrication??
So could problem be dirty contacts ? What’s next step here ?

I have voltmeter and simple test light too, both newer to me , but learning more each time using them.

[Rweiss6]

I cleaned contacts on both set of plug connectors - lower one near the switch, upper connection near top
Of radiator to fan ,used sandpaper, is there better way to clean contacts ?
Wondering , was there always extension wire between switch and fan ? maybe this was added by PO at some time ?curious

One plug , black ground wire on upper connection was particularly gummy and dirty, maybe that’s problem ???
Anything else to test to find problem ?
Also, is there way to test fan operation w/o getting car very warmed up ?
Thank you Fiatspider.com !! Always huge help

[ORFORD2004]

Also, is there way to test fan operation w/o getting car very warmed up

Yes, short the wires that connect to the switch at the bottom of the radiator.

[Rweiss6]

I have done that, fan turns right on !! But is there way to see if switch turns it on when hot , other than warming up the car ? Should switch be tested somehow ?

[spider2081]

If the coolant in the overflow tank gets too low the coolant system can pull air into the system and cause it to over heat. Have you filled the overflow bottle so the spike is covered by about 1/2 inch? If so the fan should come on before it over heats. Ideally the fan comes on when the temperature gauge is showing 190. If the fan turns on when the temperature is above that but before the red area of the gauge, let the fan cycle a few times then shut off the engine, let it cool, then start it and let it run until the fan comes on again, repeat this procedure 3 or 4 times. Making sure the engine is cooled down before restarting. The engine can self bleed it the coolant level in the over flow tank is kept above the spike and the engine cools down and then heats up a few times.
I forgot to mention the heat should be fully opened or on when doing this.

[ORFORD2004]

I have done that, fan turns right on !! But is there way to see if switch turns it on when hot

Check with the test light if you have negative at the connection of the switch. Plug the test light to the positive of the battery and one wire should be negative all the time. If so, change the switch.

[Rweiss6]

Had nice drive this morning, new ICM seems to work well, no stalling.
Fan did not come on, gauge went to about 210 or more (??) few times, while idling. then I shut engine before got too hot. Maybe should have waited longer ?

While driving never got above 190. Coolant def above spike now. Fan worked when I shorted it yesterday.

I do not understand how to test fan switch. Need clarification on shorting it, and testing voltage.
I have test light and voltmeter but need instructions please. New to me but happy to go at it.

I can clean contacts again , but prob need to test switch next. They are readily avail, and if I need to switch switch, I’ll do it. Want to enjoy car w/o overheating
Thank you !!

[toyfiats]

Unless your wiring has been kludged by a previous owner you very likely have air in the system, and the only way to deal with it is to properly bleed it out. Detailed instructions on how to do so can be found with a simple search as this is a very common issue that many owners deal with by first throwing parts at it (isn't going to help as it's usually not an issue with switches or fan motors), following by either 1), kludging the wiring to have the fan run all the time or wiring in an aux switch, or 2) following the proper procedure to purge the air out, and ensuring that there are no leaks that could reintroduce air into the system and have the problem reappear.