How do I test the rad fan on my 2007 XC 70?

[AylmerQc]

I had a diagnostic done on the car by a garage and they said one of the fans doesn't turn on.
I didn't know there were two but in any case, sure enough, on a hot summer day the temp gauge climbed into the red.
How do I test this?
Does anyone have a circuit diagram?
Thanks.

[jonesg]

start the engine and run the A/C , fan should run.
If you have vida you can turn it on too.
Before condeming it , check voltage at the plug, it should have 12v constant and a few volts on the violet wire for ECM switching.
Were you driving or sitting idling when it over heated, I drove mine without the fan, it fine as long as you keep moving.

[AylmerQc]

Thanks..
I was idling...
are you saying the voltage at the plug that has a red and black wire and the smaller wire..?


I tried Unplugging " them after spreading the two side aers but it doesn't budge,,,

[jonesg]

I sprayed the plug with liquid wrench and grabbed it with 10 inch channel lock pliers.
Mine has red and black 12v constant feed , the smaller wire is the signal, don't put high voltage into the signal wire or the ecm will be toast.
Signal wire to engine ground is under 5v,
but mine showed zero v,
I traced the break to a section of corrosion under the insulation using a fox and hound signal tracer.

But if 1 of your fans comes on its likely to be a dead fan not a loss of control signal.
Look on ebay for a used fan, they're expensive new.

[BlackBart]

I traced the break to a section of corrosion under the insulation using a fox and hound signal tracer.

Wow, that’s a slick tool!

[darylrobert]

My car has one fan -> me. but as they say "two is better than one"