2003 XC70 Radiator Fan won't shut off!

**oldmankirby** · 04-14-2011, 07:39 AM

I got home last ngiht to find the radiator fan on my wife's 2003 XC70 still running. She had been home for 1.5 hours. The car did not overheat. Everything is normal except the radiator fan will not shut off.
I unplugged it and plugged it back in and it still ran. I unplugged it started the car for a few minutes and then plugged it back in and it still ran.
I am thinking it may be the fan relay. I found where the relay is, but can not get to it. It is located on the underside of the fuse/relay box in the engine compartment. Does anyone know how to get to the underside of the fuse/relay box? I removed the 4 torx screws and undid 2 tabs that appeared to be holding it inplace, but it still will not come out.

Any ideas on how to get to the underside or if I should look for another issue besides teh fan relay?

**jda2000** · 04-14-2011, 07:51 AM

replace the thermostat unit and you'll be good as new

**Willy** · 04-14-2011, 09:09 AM

I would take a look at the fan driver. Its a semiconductor device and if it fails into a short circuit, the fan will always turn.
I think the driver module is part of the fan assembly and is not available as a seperate part.
Willy

**oldmankirby** · 04-14-2011, 11:10 AM

I stopped by the local Volvo dealership today and asked them about it as well. They thought it was the fan driver as well, and you are correct you can not buy it seperately. You must buy the whole fan, $400+.

The thermostat is $126, and was their next guess.

They also showed me the schematic of how the fuse/relay panel is attached.

So tonight I will start by removing the relay and switching it out with another relay, all the relays on the bottom are the same. If that doesn't resolve the issue, I will move onto replacing the thermostat, although the bottom screw looks very difficult to get to. If that doesn't fix the issue I will move on to the most expensive part the fan. I will post a reply tonight with an update.

Thanks for the quick replies.

**Chilled Man** · 04-14-2011, 04:08 PM

Thermostat or ECT sensor ...

**Willy** · 04-14-2011, 04:36 PM

As far as I can see, there is no relay, only the fan module (4/71)
Willy

**oldmankirby** · 04-14-2011, 09:17 PM

So tonight I went out to the car to get started and when I plugged the fan back in, it did not start running? I drive home and parked in the driveway, turned the car off and the fan also went off. I later brought my wife out to show her and once I turned the a/c up far enough to turn the fan on it once again would not shut off.

On the lid of the fuse box in the engine compartment there is a diagram of the fuses and relays. I assume since there is a relay labeled radiator fan on the diagram, that there is a relay. I will know for sure once i get it apart.

**oldmankirby** · 04-18-2011, 05:12 AM

As Willy said there are no relays. I got the fuse/relay panel out and looked at the underside and even though the lid says there are relays there are not, just plugs for the fan to plug in to.

I took the connection off of the sensor thinking that if it is the sensor removing the connection should stop sending the signal to turn the fan on. It did not.

So the next step is to start replacing things. Does anyone know if it is possible to get the thermostat kit off without removing the power steering pump?

**Chilled Man** · 04-19-2011, 04:38 PM

Originally Posted by oldmankirby

As Willy said there are no relays. I got the fuse/relay panel out and looked at the underside and even though the lid says there are relays there are not, just plugs for the fan to plug in to.

I took the connection off of the sensor thinking that if it is the sensor removing the connection should stop sending the signal to turn the fan on. It did not.

So the next step is to start replacing things. Does anyone know if it is possible to get the thermostat kit off without removing the power steering pump?

Nope not on 02+ cars

**oldmankirby** · 05-06-2011, 05:41 AM

FIXED:
OK so a few weeks ago I plugged the fan back in to start up the car and the fan didn't turn on. I thought the issue had resolved itself untill last weekend. We drove into NYC and were sitting when I noticed the car start to over heat. Apparently the fan was not working at all now.

So last night I replaced teh radiator fan assembly and everythign appears to be working now. The fan comes on when it is supposed to and shuts off when it is supposed to.

Thank you to everyone who replied with tips. Also Volvo had the fan for $400.00, but I talked to a mechanic friend of mine who suggested RockAuto.com and it was $120.00 from there, plus $8.00 shipping. Not trying to plug anyone, but thought it might be useful to know.