2002 xc70 cooling fan stays on

moto77 · Post by **moto77** » 15 Jul 2012, 13:58

Cooling fan on 2002 XC70 will not stop running. What and where to check?

Post by **DGM** » 15 Jul 2012, 15:01

moto77 wrote: What and where to check?

Normally when the cooling fan stay on it indicates a defective control module. You can stop the fan by disconnecting the connector with the black and red wires on top of fan shroud. However you can't use the car in high heat and dense trafic because the engine will overheat. The module is controlled by the magenta wire connected to the ECM. The signal is pulse width modulation and it can't be tested by backyard mechanics as us

. You can't do much about it other than finding a used fan assembly in a recyling yard or to buy a brand new one. The module is hardwired to the fan motor. In 2005 Volvo recalled many cooling fans installed on the 2001 models. I don't know if its extends to the 2002 model. May be you could verify with your dealer if your year/model (VIN) is included.

http://www-odi.nhtsa.dot.gov/cars/probl ... mmary=true

http://www.fcpeuro.com/products/volvo-a ... 0-30680547

Post by **jimmy57** » 15 Jul 2012, 16:09

When you say it would not stop running, how long did it run or did you unplug it or disconnect battery after low long?

A couple of things: the fan can run as long as 6 minutes when the engine load was high or the coolant temp was high in the last few minutes before ignition off.
You don't mention a check engine light as that would add some other conditions to the fan running after ignition is switched off.

If the fan was running for more than 6 minutes then DGM listed the usual cause.

moto77 · Post by **moto77** » 15 Jul 2012, 16:31

Thanks,
No check engine lights and the fan will continue to run until the battery is dead. Where is the DGM located and how do I identify it?

Post by **DGM** » 15 Jul 2012, 17:10

You may have a hard time to find me under the hood of your car...

Just kidding!

Post by **jimmy57** » 15 Jul 2012, 17:27

LOL,
The fan control module is integral with the fan and shroud. It is all one part. The fan on that car has a transistor speed controller made into the back case of motor.
If you look down at the fan in front of engine you will see the light violet small gauge wire plugged into what looks like a brace of the fan shroud. There is a large gauge two wire (red n black) connector. You could unplug the violet wire to see if it stops (probably not) and if it does not then you can unplug the big wire connector as that is the power and ground for the motor and that will definitely stop it.

moto77 · Post by **moto77** » 15 Jul 2012, 17:33

Unplugged small wire and it did not stop it. Noticed that are several fan units for sale on E-bay. Is it a safe bet that the problem is there or should I take it to the dealer and have it located. I would hate to spend the money on a new fan unit only to find out it is a control unit or sensor.

Post by **jimmy57** » 15 Jul 2012, 17:52

ECT sensor would turn on check engine light and fan would shut down after 6 minutes.
A problem with the wiring from ECM to the fan would make it not run at all.
Unplugging the violet ECM signal wire to the fan module and it not stopping means the module is it.

Some of the Ebay listings are wrong. The one you need will have the rectangular metal thing above the round motor (I was wrong, the totally integrated module built into the electric motor was a couple of year models later)
You need to call a dealer tomorrow first. With the 17 digit VIN they can tell you if the fan recall applies and if so, if it has been done.

Post by **DGM** » 15 Jul 2012, 18:22

Right, as Jimmy57 said you need the assembly with the module on the side as shown on this picture. Also with this model there is two types of electrical connector. In the older version the power wires have their own connector and the control wire has one. In the newer version all wires are bundled in the same connector.

: Cooling fan assembly; 30680547.jpg (10.19 KiB) Viewed 11216 times

moto77 · Post by **moto77** » 15 Jul 2012, 18:36

My thanks to all for the great help. Tomorrow I will check with Volvo about the recall, then check with the local salvage yards.
It is nice being retired and having a little time to work on my own vehicles.