fan runs on and on and on and on and......

vooman · Post by **vooman** » 09 Sep 2011, 18:33

As my 2002 s60 is approaching 105,000 miles, I wish I had stuck to my plan of getting rid of it before it hit 100k. In the last 3k miles I've had to replace the rear 02 sensor, control arm, 2 front tires & fuel cap. I know I also need to replace some unidentified front suspension parts (serious knocking) and all brake pads & rotors.

Another new part was installed just yesterday - a new battery. It was replaced because the old one wouldn't keep a charge - or so I thought. But then the new one also went dead. It occurred to me that the cooling fan was staying on an awfully long time after engine shut down. At first this didn't seem like a big deal, often the fan would run for some time, and even turn off and turn on again. Just another odd Volvo quirk. But this time I had it checked out and the mechanic informed me that I need a new fan assembly - it lists from $225 - $410.

Now I am going to sell the car - soon. But until then what stop gap measure can I take to keep the fan from running on and on and draining the battery? Maybe just hook a +12v to the fan from a source that's only hot when the key is on? Or is it possible to leave most of the fan unit and just replace the thermostat or relay (not the separate relay - it's fine)? Any other cost effective "good enough" fix out there?

Thanks.

Post by **precopster** » 09 Sep 2011, 19:02

I would have thought the coolant temp sensor might be the first stop. Another stop might be the fan relay. NEVER would I change a powered device until I check the CONTROL of that powered device.

If the fan comes on fine during running of the engine, kicks in and then turns off a minute or two later when the coolant is cooler the fan is not at fault.

Is the car overheating and is the fan running excessively with the engine ON?

Similarly you wouln't replace the fuel pump if it were running with the engine off because something is TELLING the fuel pump to stay on, usually a relay with control from the engine management system.

vooman · Post by **vooman** » 09 Sep 2011, 19:17

The car isn't overheating, temps seem to be stable and within specs.

Our mechanic says he's checked the fan relay and it's functioning properly. I gather there's a control module on the fan assembly & that's what he says needs replacing, and of course it's not available separately.

I used to be pretty good at figuring our auto electronics, but the Volo has me beat - and beat good. I break out the voltmeter, continuity checker etc. but I just can''t make heads or tails of even the simplest circuits - like the cigarette lighter. I swear they must have a team of engineers working 24/7 to complicate the whole system. They make Lucas look like a piker.

Post by **precopster** » 09 Sep 2011, 19:53

I'm selling my XC2002 at EXACTLY 160K kilomtres (100K Miles) because of all the electronics on these models.

I purchased it a couple of weeks ago and was bamboozled by the complexity of the car.

Another factor is that I bought it at well under list price so off it goes!!

vooman · Post by **vooman** » 12 Sep 2011, 12:31

I've found a replace fan on Ebay for $125. But before I pull the trigger - is there a way for me to determine that it is the fan assembly that's failed - not the relay?

Right no I have the fan unplugged, and even after the car hasn't been used for a few days when I plug in the radiator assembly it runs.

Post by **JRL** » 12 Sep 2011, 12:43

The fan works, do not replace the fan
It's a relay or something else controlling the fan

vooman · Post by **vooman** » 12 Sep 2011, 14:09

JRL wrote:The fan works, do not replace the fan
It's a relay or something else controlling the fan

The fan is part of the fan assembly, which also has a control module. So although the fan with its motor may work fine, if the attached control module is broke then the entire assembly needs to be replaced - they're not sold separately.

Post by **DGM** » 12 Sep 2011, 15:33

Most likely the cooling fan control module is defective. Find the wiring diagram for your model.

https://www.matthewsvolvosite.com/downlo ... 60_S80.pdf

On page 50 (pdf) you have the circuit. Fuse 11A/7 feeds the assembly. The module is 4/71. Presently it brings full power to the motor. It is kind of shorten out.

It is shown on page 155 (PDF) as a plug-in unit

. You've the fan on page 157 (PDF).

However i have checked with mine and the module is part of the whole assembly

.

: Coolong fan control module.JPG (63.06 KiB) Viewed 2732 times

I think you will have to change the assembly as planned.

vooman · Post by **vooman** » 12 Sep 2011, 21:24

I have the same set up as shown in your photo.

draser · Post by **draser** » 13 Sep 2011, 06:59

The fan control module is controlled by the CEM thru the purple wire. If you unplug the purple wire the fan should stop. If it does not you have a shorted out fan module. If it stops your CEM (central electronic module) is faulty. If you find that CEM may be a problem, place the voltmeter on the purple wire and unplug the temp sensor, see if there's a change.