850 electric fan in 240



  • The theory is low speed start (soft start) is to lower the initial load on the circuit.

    However it's not a major issue.

    Personally I run (I think I've mentioned it here pages ago)
    Davies craig dual thematic Efan controller.
    One pull one push. Pull turns on, push turns on 10seconds later. Both at full speed, as intended by the unit.

    Each fan has a 30a fuse, and then a 40a fuse from the power source. No melting or blowing after 3+years of use.

    I've now got the same unit ready to install on my 142, although I'll only run a single pull fan on this.
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    So you should have a big fat plug that supplies your +12V into the relay pack, a big fat plug with two wires going to the fan, a third black wire from the cam (ground), and then a plug with two small (yellow? wires).

    With those small wires, one of them will trigger low speed if you ground it, and the other will trigger high speed. Run which ever you prefer to one pin of the thermoswitch, and run the other thermoswitch pin to the chassis.

    Run the fat +12V wire to the battery along with the fat ground wire. If you don't want the fan to keep running when you kill the engine, you can find a 30A relay and relay the fat +12V onto the blue coil exciter wire.
  • So you used a generic 30A relay as well as the 850 relay pack? Just to stop the fan running when you switch the engine off, or is that a third relay?
  • GhettobirdJulian (@Ghettobird) Melbourne - SE Suburbs
    Im running the 850 fan High speed only through a Davies Craig digital fan controler, all it does is eat 30A fuses every time she goes to power on

    Startup amp draw must be huge
  • Dead/dying fan.
    Other than free, I don't understand why e everyone is fixated with using old electric fans for such a critical fit out.
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    @240 I used a generic relay only to disable the fan circuit when the car is off. If you don't mind the fan running for 30 seconds after you switch the car off, you can leave it out. On Nina's 244 I found it would switch off and then come on a second time for a few seconds, presumably from the sensor being heat soaked, and it was really annoying, so I added that relay onto the coil +12V feed so that the fans can only operate with ignition on.
  • James that's from thermal dynamics moving the coolant around the system. I've seen heat soaked hot rods run for many might items after.
  • GhettobirdJulian (@Ghettobird) Melbourne - SE Suburbs
    Its ok, Im a retard and was feeding it through the high and low soeed circuit...
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    edited February 2017
    blondejay wrote: »
    James that's from thermal dynamics moving the coolant around the system. I've seen heat soaked hot rods run for many many minutes after.

  • I did the e-fan conversion a week or two ago. Mostly good results but a couple of little things to sort out.

    1. I can't work out why, but sometimes the fan simply doesn't work. It doesn't come on when it should be triggered by the thermoswitch, and the 'emergency bypass' switch that I fitted to the dash doesn't do anything either. Nor does the light I fitted, come on.
    I think I've ruled out either of the switches - as it doesn't work at all, and it's unlikely that both switches could be intermittently faulty.
    I've checked my wiring and it's good.
    No issues with fuses.

    This has only happened twice since I've fitted it, the rest of the time it works fine. In both cases it started working again after about 5 or 10 minutes.

    My thoughts are that either the fan itself is dodgy, or the relay is dodgy. Considering the indicator light doesn't even come on, I'm leaning towards relay.
    Does that sound about right or am I missing something?

    2. Although the temperature is quite stable with this setup, I think the engine is running cooler than it should. The needle tends to sit about a quarter or third up the gauge, rather than in the middle.
    The fan only ever kicks in when I'm sitting in traffic (and there's no cool air coming through the grille).
    Would it therefore be reasonable to assume that the thermostat is just opening sooner than with the clutch fan, so the engine is not getting up to a temp where the e-fan needs to kick in?
    (I'm running an 87° thermostat and an 82° thermoswitch).
    Is this anything to worry about?
  • Just rip it out, put a davies craig dual thematic controller in there. And be done with it.
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    With the fan, get it to stop working, then try powering it directly off the battery post. That should answer the fan/relay question.
  • On the latest episode of "engine masters" on "motor trend on demand" they dyno an engine with various mechanical fans and without. Pretty interesting. Should be on youtube in a month.
  • jamesincJames (@jamesinc) Oz Volvo Ice Fortress
    The viscous coupling fan predictably wins though. A little silly that all their fans didn't have the same blade pitch!
  • The difference between fan types/pitch was interesting, but the difference between fan and no fan made me a fan.
  • "no fan" vs "OE type clutch fan 18" with 6 blades"
  • Thafs on a rather large truck diesel fan no?
    18" is very large. A smidge under double factory size.

    Though yes I do still agree. Mostly it's the constant noise a clutch/fixed fan makes.
  • Vee_QueVee_Que (@Vee_Que) South Eastern suburbs Melbourne.
    82 degree switch is your issue there. However, it doesn't affect the thermostat itself.
  • Interesting that you should say that...
    As I said, the engine seems to running cooler (about a third up the gauge but the fan doesn't kick in then - only when I'm sitting in traffic and the temp goes up more.
    In other words it can't be the 82° switch can it, because the engine isn't even getting to 82°...
    With the fan, get it to stop working, then try powering it directly off the battery post. That should answer the fan/relay question.

    Tried this today but when I went to unplug the wire from the relay (to put on the battery post) I heard some sort of click as soon as I touched it and the fan started. I can only assume that by bumping the potentially faulty relay I caused it to work again, does that sound possible?

  • lasercowboyRico (@lasercowboy) SE Suburbs, Melbourne
    Check your earths. If it suddenly clicked over when you touched it, could be a dodgy ground connection?
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