240
@jamesinc what configuration did you use the 850 relay in? Wiring diagrams I've found call for a relay with pins 85, 86, 87 and 30, but the 850 relay only has 2, 1, 2, 1, 30...
If anyone has recommendations on a suitable thermoswitch that'd be great.
OldnDecrepit
I've just rewired mine with the Volvo relay and the fan won't turn on when the engine is running. Seems like the relay is designed to use a different thermoswitch than the Davies Craig one. So now I have to get a Volvo thermoswitch or go back to my old relay - sigh!
DCW242
the trigger wires on the Volvo relay are meant to be earthed out to trigger the relay, it won't switch on if you put power into those wires. I used a standard Bosch relay for mine, that way I could run power to the switch and use the out put of the switch to trigger the relay.
Vee_Que
jamesinc;69437 wroteI'm going to swap my thermostat for an 82 on 74 off and see how that goes.
@Slowbrick I didn't think to swap in a lower-temp thermostat (OE is 87 right?) does that have any other side-effects?
Edit: also, you use a Datsun coolant bottle right? Do you know what pressure your system runs at? Reading online looks like it makes a difference if you run the black or green coolant cap.
I've had an 82 in my 740t with mechanical fan for 100k. Its great for Australia. Had a few near misses over time and it hasn't cooked etc.
jamesinc
Oh yeah I should update. So with the new thermoswitch it works well. Temp consistent, fan only really cycles on/off in slow traffic.
240
What's the new thermoswitch that you've used?
jamesinc
82 on 74 off
240
With what thermostat?
jamesinc
87 degree thermostat.
240
Thanks.
Any chance if a link to the new thermoswitch you bought? I'm having trouble finding one.
jamesinc
240;70763 wroteThanks.
Any chance if a link to the new thermoswitch you bought? I'm having trouble finding one.
I bought from eBay
http://pages.ebay.com/motors/link/?nav=item.view&id=231534349103&alt=web
240
Thanks!!
Just need to find a 740 Turbo fan shroud now.
240
How much current does the fan draw? Will 15A wire be OK to use or should I buy some 20 or 30 amp stuff?
The other thing is that a lot of wiring diagrams I've seen call for a connection to the battery. I've never done this before, how is it done? Seems a bit dodgy just connecting a wire straight to the terminal. Forgive my ignorance please!
DCW242
240;71205 wroteHow much current does the fan draw? Will 15A wire be OK to use or should I buy some 20 or 30 amp stuff?
The other thing is that a lot of wiring diagrams I've seen call for a connection to the battery. I've never done this before, how is it done? Seems a bit dodgy just connecting a wire straight to the terminal. Forgive my ignorance please!
I haven't actually tested that, I used a 30A fuse and wires on mine. I would say 15A is probably too low.
jamesinc
The wire I'm using is rated for 17A and doesn't get warm or anything, but I dunno assume 20A.
240
Planning to do this conversion in the next couple of weeks
@jamesinc maybe I missed it, but with speed did you use on the 850 fan, low or high?
jamesinc
@240 I used high speed. I found on low the temps were creeping up quite a bit before the fan got a handle on things. You'll reduce load on the circuit if you spool up low speed first (like, 2 seconds ahead of high). A relay could do it, or you could just relay low speed to ignition.
Also I ran power directly from the battery post. I was running it from the power rail initially, but it was causing large voltage drops everywhere when I did that.
deleted_user_160
Some of the relays will utilise the 3 wires to control the speed, two trigger speed wires for essentially what is a soft start for the fan.
In saying that it's not a huge concern, lots of us and thousands of others are using single full speed e fans successfully every day.
240
Sounds like high speed only is the best way to go then once effectiveness and ease of installation are weighed up.
(Or is the initial load reduction on the circuit necessary to avoid blowing fuses?)
James you didn't use the 850's fan relay, just a generic one?
jamesinc
I used the relays from the 850 also. Nice to have nice plugs on everything.
