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850 electric fan in 240
Duncan @DCW242
- Ballarat
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:
<h3>Switching</h3>
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.
http://daviescraig.com.au/product/mechanicl-thermal-switch-part-no-0401/mechanicl-thermal-switch-part-no-0401
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:
<h3>Switching</h3>
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.
http://daviescraig.com.au/product/mechanicl-thermal-switch-part-no-0401/mechanicl-thermal-switch-part-no-0401
Comments
This is really useful. Keep in mind that v70 series cars also have a shroud with an unboltable fan and I may be wrong here but I think these are slightly skinnier.
Most Saab 900s that I have seen have this coolant t peice but as a rule it is usually pretty corroded.
The next question is...Can I use the stock 850/V70 coolant sensor and 850/V70 relay located just above the radiator shroud to provide a dual speed fan control?
Looks really clean and stock though Duncan nice work!
Cheers,
Sam.
I think the way relay works is, the two smaller yellow wires are trigger power for each speed, so power into one of them will trigger one speed, and power into the other will trigger the other speed.
At the moment I have a 3 pin switch, which has a power in, and a power out at 87 and at 93. My 240 also has aircon. I have the factory 850 two speed relay, but I'm not sure if it's worth fitting it. I have mine as single speed at the moment, I'm not sure how I would have it set up if I did two speed, but it's definitely possible to use the 850 relay.
Yeah.
Tomorrow I'll get some rubber edge trim, like on 240 door frames, and fit it around the edge of the fan. I don't how that will go but it's worth a try.
My car has the second electric fan in front of the condensor, so I was going to set that to run whenever the A/C was on. It will help with cooling in the summer and should also make the A/C work better. I don't know yet if the 50% speed will be sufficient for my 740 as I haven't yet experienced it in summer with this setup.
People used to cut down the vn-vs commodore fan but times have changed a bit since then.
Seeing as Masters has folded, I went to Bunnings, and got M6x16 SS bolts and M6 nyloc nuts, as well as the curtain hanging brackets (20mm size). Total spend $19. Could be done for much less if you used regular HTS bolts. I think I will add some washers to the setup as I don't like the bolts biting into the plastic.
How does one wire up the fan?
The commodore one would flow more air but overheating doesn't seem to be too much of an issue either way.
With the 850 fan you have the ability to use the stock relay/sensors also.
this combined with the fact im drawing air through Ac condenser, 75mm intercooler, and then the triple core radiator, i added a large push fan to the front of the Ac condenser to assist.
all working using the davies craig dual thermal fan digital switch. this sets the pull fan to come on at a desired temp (mines set at 85deg) then 10sec later the push fan comes on until the coolant temp drops below the set temp. that and because the temp sensor is placed in the hot side rad hose (correct fitment) this allows longer cooling and by the time the temp drops blow the set number, the coolant already traveling past the radiator is now cooler. i have seen the temp sensor read as low as 77deg before climbing again, and fans beginning the cycle again.
Also how should an electric fan be wired in?
Like I said I'm using the dual thermal digital unit.
Leave your current setup, you gain 2hp and more room for failure.