How to test your engine fan to make sure it works so you don't overheat your vehicle engine. - VOTD

[@OnyxDavid11]

One thing I found was that EM fans can run almost forever what happens in computerized systems is planned obsolescence. For instance, when your cooling fan is connected to a control module and it fails, it doesn't mean the fans have failed. When EM fans get older, they don't stop working but what happens is they may draw more power. When the ECM picks up on this, it "fails" the fan by refusing to supply power to it. Effectively, you could bypass the fan control and plug right into the aux power to the control module but then you will lose speed modulation. Best bet, get new fans. Clip the plugs off the old fans and splice them onto the new ones. Plug right into the control module and it will run like OEM. Cheers.

[@RobertDIY]

Thanks for sharing

[@AwakeDude911]

pretty sure if you follow the green and red wire into the harness on the front driver's side there is a connection ( unplug )that plugs into it so that whole section is an extension wire . its backwards so you can cut that out of a bone yard car and check fans all day long as it just plugs in the fan original grey box and and a jump box and in 30 seconds you can tell if it works or not....came across a lot that were seized up in the bone yard. saves alot of hassle .....just my 2 cents..

[@RobertDIY]

Awesome tips. Thanks.

[@brianklamer3328]

On a hot day after in town driving & running the A/C it's common for my C70 or V70 Cross Country to have the fans run a minute or so after shutting the car off.

[@RobertDIY]

yes it is.

[@tedwu9354]

The 2 speed fan control module has a hot 12 volt connector on the right. In the middle is a ground connector to control the relay to feed the power from the right connector to the left connector. If you disconnect the middle connector, run a small wire from the oil stick tube and touch the middle connector in the fan module, the fan will operate. Connector 1 is low speed, 2 is high speed. I made a manual switch to control the relay because I have p0480 and p0481 code for fan circuit problem.

[@RobertDIY]

Interesting

[@wheelsup]

Yep I just found this out tonight. I tested the relay and it's good so I'll just wire up a switch.

[@tedwu9354]

@@wheelsup Sounds good. I bought a electric switch from Home Depot. It's exactly the same switch you use at home to turn on the light. Cost is like 85 cents. Then I used a few USB cables and power adapter cables. I solder together to make one long cable from the relay to the switch I put underneath the steering wheel. I made a short cable and connect from the negative terminal of car battery to the switch. Good luck on this small project. It works really well for me.

[@bernardaflores1720]

The location of the relay above the fan shroud is a magnet for heat if you can add some reflective sleeve to minimize the temp on the wires.

[@RobertDIY]

Interesting

[@chippywarren9706]

Thank you Sir for the explanations and ideas. 👍

[@RobertDIY]

You are Welcome!

[@jeremiahlyleseditor437]

Great Tip Robert. I have a slightly different setup though. It's a 740 GL

[@RobertDIY]

I understand

[@Godjes57]

Thank you your video was very helpful and easy to understand thank you for your help 👍🇺🇸

[@RobertDIY]

Very welcome

[@_Mark_H]

Simple but very helpful advice. Thank you Robert 👍🏼

[@RobertDIY]

Very welcome

[@poopathyraaja9949]

Thank you for the information 🙏.

[@RobertDIY]

you are welcome.

[@tinakuutonen]

How can I test the signal wires that goes to the middle of the relay ? My car is 1997 (model year 1998) Volvo V90 and though the fan is working when I test it the way you showed and the thermostat and temperature sensor are OK the fan won’t cut on. Neither when A/C is on nor without it 🥲 I even purchaced a new 2-speed relay and installed it but in vain,,, When I disconnect the temperature sensor and start the engine the fan cuts on and stays on untill when I stop the engine and wait for six minutes. I guess this is somekind of safety feature in case the sensor or its wires are damaged.

[@RobertDIY]

Wow! That's nice. I need to learn how to use the app.

[@RobertDIY]

Yikes! Sad to say, I do not know. May be a problem in the ECU.

[@andresbasti5061]

Hello. I have a 2002 Volvo v70xc, the fan does not work and the air conditioning does not activate either. You can show how to check it, the system is a little different from the one in the video.

[@RobertDIY]

same theory. you can figure it out or bring it by and I'll help you.

[@kevingrace2542]

Can you test the ac preasure sensor with vida

[@RobertDIY]

maybe

[@edwarddunlap5420]

Robert, excellent video. I have a 2000 S70 2.4 litre 5 speed. Checked my fan by connecting it as you did and it works great. A few questions, first, should the fan go on if the A/C is turned on regardless of the temps? Second, on your relay you have what looks like a stoplight with the top two lights filled. My relay is so old that I cant read anything on it except the stoplight symbol. One mine however ALL three lights are filled. All the sources I have looked at give a part number of 9442933. Is this a 9442933 part?

[@RobertDIY]

I don't know.

[@dawnrobbins5877]

Good stuff Robert! ✌️👍

[@RobertDIY]

Thanks 👍

[@user-nw7kf6nl2y]

Is it normal for the upper radiator hose from the rad to the thermostat housing supposed to get hot and swell?

[@RobertDIY]

Not really. I would make sure you have an OEM thermostat and a newer hose.

[@RobertDIY]

kzbin.info/www/bejne/jYmyeZ2bhbqKobc

[@ocean5377]

Got a v70 overheating, petrol 2004 , 2.4 I think I have trans oil in the coolant reservoir, any thoughts

[@RobertDIY]

maybe it has a bad radiator.

[@thesweckd85]

Great info 👍

[@RobertDIY]

Glad you think so!

[@alfredodelarosa9489]

@@RobertDIY traducir al español

[@jollyrodger5319]

Those signal wires are the problem for most fan problems and all of us from the '90s through early 2000s. They rot their old always check them. Will cause resistance in the relay in the relay will burn out prematurely had this problem many a times 940s 960s and my V70 . The temperature sensor on the 850s 960s also feeds the computer information on fuel injection check there

[@jollyrodger5319]

As a side note green wire stripe on those little leads is your low side the yellow with the red stripe is your AC high side when you're repairing those leads back into the relay

[@RobertDIY]

thanks for sharing.

[@jonathanfernando-k3b]

i bought a new relay changed the thermostat but nothing still doesent work.COULD IT BE THAT THE GREEN WIRE IS DAMAGED?

[@RobertDIY]

My guess would be that the low side of the fan does not work.

[@jonathanfernando-k3b]

@@RobertDIY any clues to why the low side isnt working? oh and btw THANKS A MILLION for responding

[@jonathanfernando-k3b]

@@RobertDIY could it be the ECU at fault?

[@louisjames1062]

On a vw or Audi you just need to unplug the hvac unit, this automatically put fans on full

[@RobertDIY]

cool

[@SmokeShellGaming]

I drive a 2010 Volvo S80 3.2 and I'm not entirely sure if the fans are kicking on or not. Whenever I open the hood to check I don't see the fans spinning, even after hard driving. Is this normal?

[@RobertDIY]

Yes, you can connect a tool to the OBD2 and check the coolant temperature. If it's above 230 degrees the fans should be running. You can also turn on the AC. If the AC is on for longer than 10 seconds the fans should kick on.

[@jonathanfernando-k3b]

in my volvo when i did this to see weather the fan was working the high speed worked but the low speed didnt i need some help please

[@RobertDIY]

Bring it by ..

[@jonathanfernando-k3b]

@@RobertDIYbeleive me i would bring it to ya but i live in italy 😔

[@johan2141]

hey Robert, is it a wise move to put my v70 from 2000 in the garage for a year. or will this be bad for the vehicle?

[@RobertDIY]

A year would not matter. Just disconnect the battery and maybe get the tires off of the pavement (put on wood). Also add a bottle of heat to the fuel tank.

[@coreturkoane5570]

@@RobertDIY Bottle of heat? whats that??

[@jimmiles33]

@@coreturkoane5570 fuel stabilizer.

[@oldgeordiegeezer3086]

Water PRESSURE causes the cylinder to warp???

[@RobertDIY]

Excessive heat. The pressure blows the gasket.

[@jeremiahlyleseditor437]

Where is the relay for mine, if there is one?

[@evanhampton6786]

If it’s a 700 series car I think it’s in front of the battery. That’s how it is on my 940

[@jeremiahlyleseditor437]

@@evanhampton6786 It's a 740 GL. Nothing in from on mine except the headlights.

[@evanhampton6786]

Can you follow the wiring harness from the fan?

[@jeremiahlyleseditor437]

@@evanhampton6786 I can if I can find it. I'll have to search tomorrow. The temperature is 107 now. Should the fan turn on if I apply power to the connectors end?

[@RobertDIY]

Yes.

[@khalidfitory6097]

Fan cut off at 94 not 97 ..check thes inforation

[@RobertDIY]

Interesting. My Google conversion states that 206F is 96.6C.

[@mikeberger1688]

How do you get the black housing off with the connectors on it? Can't figure it out.

[@RobertDIY]

What black housing?

[@RobertDIY]

kzbin.info/www/bejne/jZekl5utp7iop7M

[@mikeberger1688]

@@RobertDIY many thanks robert.i'll try just pulling it out as shown.

[@DelVila]

❤

[@RobertDIY]

thanks

[@jlj777]

[@RobertDIY]

✌🏾