850 electric fan in 240

DCW242 · 2015-08-27T08:28:34+00:00

I used the 960 fan and a cut down 960 shroud. But I'm tempted to redo it, mounting the fan in the standard 740 shroud. I also used the Davies Craig sensor...

DCW242

Thanks! :)
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.

DCW242

Samman88;57669 wroteAlso might be worth sealing up the gap between the fan and the shroud with sliding door foam stick on strip from Bunnings if you have any overheating issues.

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.

OldnDecrepit

My understanding of the relay is that power goes in at one end (marked with 30A fuse) and the two speeds of the fan are powered at the other end (the OUT 1&2). The two IN in the middle are the triggers from the sensors.

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.

Vee_Que

You should always run the fan wit the ac, it keeps it cooler and the pump doesn't work as hard as a result. If you have removed the front fan, then you definitely just have the fan triggered to turn on with the ac signal beforw the tx valve.

People used to cut down the vn-vs commodore fan but times have changed a bit since then.

jamesinc

@DCW242 I made up an e-fan today using this guide. Haven't done the switching part yet.

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.

240

Any thoughts on how this method, using an 850 fan, compares to using a Commodore one, as per this thread?

jamesinc

@240 I'd say the biggest difference is that this solution has a lower side profile. The reason I'm doing it this way is to solve the problem of shroud clearance when adding an intercooler to a 240 for +T

240

OK then.
How does one wire up the fan?

Vee_Que

No, masters is definitely still around!

egads (she/her)

Yeah, only stuff that seems to be being wound down a little from my visit today is their appliance lines

Samman88

I think perhaps the 850 fan is neater as you retain your stock shroud rather than butchering a commodore one.
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.

deleted_user_160

i used the 960/850 fan. as the pull, mounted in the 740T shroud, until it failed, (constantly blowing/melting fuses when it switched off) then referred to a generic unit of the same size, of which i mounted with out the shroud, simply because it has its own protection grille, and the ver very small amount of area it doesnt cover is so minimal that its of little worry.
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.

OldnDecrepit

The Davies Craig setup has one failing. If someone bumps the controller dial and turns the fan down the temps can rise pretty quickly. Just had this happen to me and I suspect that the auto electrician working on the battery may have accident bumped the dial.

240

Has anyone else had this issue with the 850 fan? I was thinking of tracking one down because it sounds like a fairly straightforward fitment, but I don't want it blowing fuses all the time.

Also how should an electric fan be wired in?

deleted_user_160

Not at all. The Davis Craig unit I'm using is this. If you can bump the temp setting button, you have broken your two relays.
Like I said I'm using the dual thermal digital unit.

Vee_Que

240;67475 wroteHas anyone else had this issue with the 850 fan? I was thinking of tracking one down because it sounds like a fairly straightforward fitment, but I don't want it blowing fuses all the time.

Also how should an electric fan be wired in?

Leave your current setup, you gain 2hp and more room for failure.

jamesinc

I'm going to use this thermostat to switch high speed

http://www.summitracing.com/int/parts/der-16731/overview/

A_Volvo_Driver

I'm just going to get one of you guys to sort this out for me. It might as well be magic.

DCW242

Thanks guys!

@jamesinc - I later fitted a set of washer to my fan shroud bolts, after I fitted the bolts they did cut into the shroud a bit.

240;67423 wroteOK then.
How does one wire up the fan?

That part is fairly easy, there's some wiring diagrams on a few Volvo sites. Dave Barton has a few of them on his website. basically you will need a relay, some kind of temp switch, the fan, and some fairly basic wiring. there's a few ways to do it, and it depends on what kind of relay and switch you use. basically you will need to power the relay via a fuse, power the fan from the relay, and switch the relay using the temp switch.

At the moment I have an 87° switch in the lower hose, and two Bosch relays. one for each speed. with the higher speed connected to the temp switch, and the lower speed connected to the aircon. that seems to work pretty well, but once the fan has ran for a bit and switched off again, the temp gauge is pretty low. so I might have to get a temp switch that switches off at a higher temp.

I'll take some better pics of my set up and update the post.

Angus242164

A couple of old diagrams here that I drew up 10+ years ago when playing with electric fans on my 242:

In both of the elec fan conversions I've done I added a switch on the dash to allow manual control of the fan, if the temp switch ever failed. I've never needed to use the feature, but it's nice to know it's there. In the 242 I added an indicator LED too, for no good reason.

For what it's worth, this is the aftermarket fan I've had on my 760 Turbo for the last 8 or so years:

As you can see there's no shroud, and no air gets drawn through the corners of the core by the fan, but I've never had any overheating issues with the car, even in traffic in 40 degree heat etc.

The point I'm trying to make is, don't worry too much about perfecting airflow through shrouds, they're not as essential as you might think.