JamesM Hey guys and girls. Have a 940 efan with a craig Davies digital controller I want to install in the 740t in the original 740 shroud. A little confused about the wiring side of it. I understand they draw a lot of current initially and when high speed kicks in. Just after advice on how to wire this in. It would be great if I could have a manual override in the cabin to switch between low and high along with an indicator light to tell me when the fan is on in case I don't hear it kick in. The controller comes with wiring instructions but I was wondering if anyone here can help shed light on this. What sized wiring should I use and should I use any extra fuses etc. 12v constant from alternator +. 12v ignition from ignition coil spade. Ground to ground. 30amp fuse for each speed. What am I missing? Regards James
jamesinc What does the fan say it needs for current? I normally take 12V from the battery terminals rather than the alt itself, it makes for easier wiring and fuse location. Otherwise you want fuses rated for the wiring. A circuit breaker is also a decent alternative.
JamesM Thanks @jamesinc I'm not sure but it's just a stock 940 fan. I was considering the alternator that way it won't stay on when the car is turned off. Also it still has the wiring for the circuit breaker for the amp installed. So you think it would be a bad idea to have the fan AND the amp running off the one breaker?
jamesinc @JamesM yes I would always try to isolate the fan circuit from other concerns (especially something like an amp). The alternator +12V is always hot, even when the ignition is off. I don't know what IO your fan controller has, but with simple SPST relays it's not too complex. When I wired Billie, the supply line was rated for 50A and I used a 40A breaker and 40A relays with an 850 e-fan which I think is pretty similar to the 940 one. I'll draw a diagram.
jamesinc Someone confirm my LED circuit will work Edit: ignore my note about the diode, this circuit would be fine with either an LED or a conventional bulb, as effectively it's just a bulb run in parallel to the fan.