I thought it's worth making an article on this.
How to fit an 850 Electric fan in a 240, and some 7/940s with the same radiator.
I think they are the same fan as used on some 960s/S90s/V90s, and 940s.
I like the 850 fan because it's a good size for the 240 radiator, easy to mount, cheap and easy to get.
<h3>Mounting the fan</h3>
I mounted mine in a 740 Turbo fan shroud, which worked well since they're very similar in size, so very little air gap. and the 740T fan shroud is pretty short so the whole set-up ends up being pretty low profile.
To hold the fan into the shroud I used four L brackets. I got them from Masters, I think they are sold as curtain brackets lol.
Using M6 bolts, you will need to drill holes in the shroud, you will also need to drill holes in the fan. Depending on where you want the wires to come out of the fan you might only need to drill two holes in the fan. I also had to in large the holes in the L brackets a bit, depending on the brackets you have you might need to do that.
And the whole set up:
The 740T shroud bolts up the same as the factory 240 one.
Fitted to the car:
The 850 fan is two-speed, but I choose to run it single speed. the green wire is half speed power, the red wire is full speed power, and black is ground.
I guess there's 3 main ways to switch it.
The first is to use the T-piece in line fitting from a Saab 900, and put it in a radiator hose. and use a standard aftermarket M22x1.5mm fan switch. this is cheap, easy, and reliable. but that doesn't look great, and if you want it to come on at a different temp you have to get another switch.
The switches are really easy to get, They're used in lots of cars, and lots of good aftermarket ones available.
The Saab T-piece may not be so easy to get, since they corrode. I'm not sure if they are used in all Saab 900s, Hopefully someone who knows more about Saab's should be able to help with that.
I have this set up on my 240, it seems to work really well. I have an 87 ° switch and an 87° thermostat. I prefer to put the Saab switch housing in the lower hose.
Here's some pics of my set up.(without wiring connected)
Another way is to use a coolant temp sensor in the head, and a Jaycar kit that uses that signal to trigger the fan relay.
This is looks nice, is adjustable, and reliable, but a bit more expensive and you need somewhere to mount the sensor in the head.
Angus (@Angus242164) has this on one of his Volvos, so maybe talk to him about that. I might use that system later on.
The other way is to use a bulb type sensor in one of the hoses. Like the kit linked below. I don't really like that system, since it's easy for it to leak, and it doesn't look great.