Electric Radiator Fan - always running when engine is on

[tmurph05]

Hi,

I'm new to volvos and servicing them. I recently noticed my electric blower fan (right in front of the motor) is constantly running while I am driving. The a/c is off (at least the light is and the compressor doesn't seem to be engaging) and it is also winter here. What could be causing my electric fan to run all the time and how can I fix it? Thanks!

[ericjp]

There should be a control wire that I'm thinking is pink connected to the fan. If you disconnect it and the fan still runs then the controller is bad and you need a new one.

[tmurph05]

I disconnected that wire, and the fan turned off. What does that mean?

[tmurph05]

Well, I disconnected the entire wire hub (red black and pink) are you suggesting I only remove the pink wire?

[ericjp]

Just the pink one, its the signal wire that tells the fan to turn on.

[tmurph05]

How do I remove it without damaging it?

[ericjp]

You need to depress one side of the connector and pull it out.

[tmurph05]

Is this the pink wire you are talking about? It's hard to pull out.. I don't want to wreck it.. IMG_5530.jpeg
5863

[ericjp]

There should be another connector in that wire further to the passenger side. It should be clipped onto the fan shroud.

[tmurph05]

That wire terminates on the fan, and plugs in there. If I trace it backwards, it heads to the drivers side. Is there another wire?

[ericjp]

That should be the correct wire. Can you check to see if it has 12 volts on it?

[tmurph05]

Yeah, the red and black supply the 12 volt power to the fan.

[ericjp]

Do you have 12 volts between the pink wire and ground?

[tmurph05]

Oh, I have a voltmeter, but no idea how to determine the answer to what you just asked me. Brakes, carbs, pistons and all that stuff I can do, electrical is my crutch.

[ericjp]

Set your voltmeter to volts DC. Black lead to ground, and red lead to where the pink wire ends, or where that nick in the insulation is by the connector.

[tmurph05]

Okay, I'll do that when I get back into my garage. While the engine is running/key on? I should probably mention I don't seem to be having the same problem as some people with it cunning when I turn off the car. It runs on high when the car is on but not when the car is off. Additionally, if I clear the engine codes by disconnecting the battery (because after unplugging the fan the engine light came on, so I knew why) then it functions appropriately for a short while.

[ericjp]

Did a little more research and the pink wire shouldn't have 12 volts on it, so disregard what I said about that. You could have a defective coolant temp sensor telling the fan that the motor is hot.

[tmurph05]

Where is that located?

[ericjp]

I believe it's around the thermostat housing. Do you have a scan tool? Most of those will show you what the car thinks the coolant temperature is.

[tmurph05]

I so not, looking at ordering one online- any suggestions? I have a buddy who will read it for me Tuesday. I'll update then. For now I just have the fan unplugged so it doesn't run at full speed all the time.

[nickbw]

I so not, looking at ordering one online- any suggestions? I have a buddy who will read it for me Tuesday. I'll update then. For now I just have the fan unplugged so it doesn't run at full speed all the time.

Change you coolant thermostat and your temp sender. It would also be appropriate to renew your coolant at the same time. The very complex electronic circuitry that controls the coolant main radiator fan is prone to catastrophic breakdown. The entire fan/shroud assembly is very easy to remove/replace and these units are readily available via the used parts market. These systems are not amenable to DIY fixing. The so called "relay" is not a relay in the conventional sense of the word but a very complex electronic system which is hermetically sealed. First establish the veracity of your diagnosis, second replace the components for known good replacements.

[Antherzoll]

Check the charge on the A/C system. Even though it's off, the system can still run the fan.

[dpaton]

Please stop creating multiple threads for the same issue:
http://www.volvoxc.com/forums/showthread.php?25618-Cooling-fan-always-runs-full-speed

[tmurph05]

It turns out the problem was my air intake temperature sensor - it was reading 169 F in minus 20 C weather. All is well! Thanks everyone!