Electric fan conversion..has anyone done one?
 

Hi all,
I'm keen on wrestling a teensy bit more economy (yes, I hear you laughing...) from my 744 and 245 as I'm doing around 5000 miles a month at the moment due to my insane work schedule. I'm very tempted to do an electric fan conversion, as much as I love the sound of the viscous coupled fan I know it's just spinning there and creating parasitic power loss.

Has anyone done the conversion? If so, can you advise on how straightforward (or not) it is, and which are the best parts to use?

Thanks in advance for any and all advice!
Phil

I did the conversion on mine.

I think there are 2 widths of radiator so make sure you get the right fan width :)

I used the standard 2 speed volvo relay, and one of these in the radiator hose:

https://foundry4x4.co.uk/index.php?r...ch=thermostat+

On the diesel it's a very tight fit, I imagine it's a lot easier on a 4cyl :)

Re your 240. I understand Nicholas Lewin upstairs in the 240 section has fitted an electric fan. The last that I heard he was having to fine tune the installation. It could be well worth your while to contact olde Nick

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I've fitted a number of fans to various 240s: the 940 fan motor needs a 35-amp fuse and draws a LOT of current but brings the temperature down very quickly.

You can either wire it to an accessory-live circuit, with its own switch (my approach), or use the sensor units from a 940 and wire it into a permanently live circuit.

Physically mounting a 940 fan is best done by acquiring the fan and associated mounts. The shroud can always be hacked about if it's too wide. Alternatively, you could always fabricate a set of mounting brackets for it.

What fan should be fitted to a 1997 940? My daily has an electric fan but the 1997 one I'm breaking had a viscous fan which I found I interesting, I do see is someone converted it from electric to a viscous fan.

The flippant answer is "whatever was lying around at the time". Most of the cars by that time should have had electric fans fitted although a few might not. Earlier, normally-aspirated, engines had viscous fans as a rule.

If there's a set of 3 electric sockets on the radiator then the car's been modified to carry a viscous fan, possibly because the fan motor died and no replacement was available.

Well worth doing Phil! Everyone else has explained the "how" and the "what" but i've found on both my last 740 and this 760, removing the vicious coupled fan has resulted in firstly thinking i've gone deaf, secondly a pleasant surprise when prodding the loud pedal and thirdly, an even more pleasant surpise at the filling station!
Average improvement has been 10-15% depending how/when/whee i've been driving.
On the 740 i didn't even bother fitting an electric fan as it stayed cool enough just from forward motion of the car and likewise on the 760 although the electric fan for the air-con has cut in on high coolant temp a couple of times when i've been stuck in traffic.

I keep meaning to finish the addition of an electric fan, i have a 92-87C switch mounted in an alloy coolant hose sensor adaptor with 32mm stubs to fit in the top hose. The important bit when using one of those is to mount it so the sensor face is pointing up (connector socket/wiring down) so the coolant runs over it at all times.

Then i'll use the switch to operate a relay that powers the fan. Just need to find a fan now............ :thumbs_up:

electric fan
 

I thought about having a go and some kind chap actually sent me a write up on how to actually do it - shortly thereafter the computer went pop..
If you look up davebarton.com he does some wiring diagrams and chats generally about conversions, which may give you some ideas.
If you get it done please do a write up in a 'for dummies' style so I can follow.

jor

rather than fitting an oem volvo unit, I'd go with an aftermarket kit. It will have everything in it you need.

Typically, you hoick out the viscous fan and shroud, and flat mount a combined fan and motor with through-bolts passing through the fins of the radiator.

Wiring, its a live supply from the battery (or more properly, the B+ on the back of the alternator), through a 35A fuse, relay and on to the fan motor + terminal. Earth the -ve terminal to a VERY good earth point - these babies suck electrons like a dyson picks up cat fur.

The relay is controlled by a thermo-switch. Make sure the switch "on-to-off" point is HIGHER than the opening temperature of your water thermostat. Typically the fan should switch on just below 100 degrees C and off 5 - 8 degrees below the on point. The thermo switch should be mounted as high in the coolant circuit as you can get it - typically it goes in the top hose.

Keep your sticky little fingers well away from the spinny bits when testing. They WILL remove a finger quite happily.

Well I'm gonna be contraversial.

You are wasting your time, the you tube comparisons of BHP loss are invalid. There are no losses when the car is moving anythihg more than about 30mph. The comparisons are done stationary.

If you want to massively improve your economy get a mpguino and learn to hypermile. Its possible to get 40mpg in a 940.