artymr2

Sorry, what do you mean by "trips the fan ECU all the time"?

also: "...but the problem I'm going to face is having a flat battery soon because of having the fan running constantly if the engines not running (when the cars just on ACC etc)"

unplugging the sensor will make the IC fan work only when IGN is on, not ACC.

Or am my misinterpreting this thing completely?
Cheers

trip fan ecu = fans stop working and a RED fan light comes ON in the dash (engine compartment fan light)
regardless of wethere the temp sensor is plugged or unplugged the fan will stop working after a while. then im basically steaming my engine lol
if i get the chance i restart the car which resets the fan ECU and all is good for another 20 sec BAH.
i have however managed to have the fan running continuosly a few times, im not too sure How or what happened.

Also, you can set up a simple water spray onto the IC to keep things cooler.

I was wondering if there was a way to run a pressure switch off boost pressure so that the fans only come on once a boost signal is detected and then keep running the fan continuosly until the car is switched OFF

Yes, that is quite simple to do.  Just setup a latching relay.  You can either use a pressure switch to do this (various sources, even from a washing machine etc if you want to keep costs low), or I used a voltage comparoator IC and a couple of resistors and used the MAP sensor output to trigger my circuit (you can make the turn on point adjustable).  I used this method to trigger the water injection.
 
Cheers

My spals in the lid are run via a relay from the main feed in the engine bay fuse box. This only comes on when acc are on and if i dont want them on i can simply unplug the adapter. My sidemount fan is running off std wiring for the factory fan and runs all the time as soon as ign is on as the sensor on the lid has been taken off.

jdmr288

My spals in the lid are run via a relay from the main feed in the engine bay fuse box. This only comes on when acc are on and if i dont want them on i can simply unplug the adapter. My sidemount fan is running off std wiring for the factory fan and runs all the time as soon as ign is on as the sensor on the lid has been taken off.

i want to run some sort of fan in the engine bay but dont want to loose the rainguard.
the temp sensor weter its plugged or unplugged makes no difference in my car, as soon as the fan starts running about 20sec later it will trip the FAN ecu.

• well id like to work or do some stuff on car and dont want to drain battery with this fans running for no apparent reason.
• plus my car doesnt get driven alot so dont want the battery going flat while tryign to start and then having to jump start the car.
• the noise annoys me when stationary (cant do much about that i guess)

pressure switch idea is dumb (sorry but it is)
 
if you want to save your battery fit a time delay switch in the new wiring (the stock fan wiring should not be used even with a davies craig, look at the wiring differences for instant reasoning and why such as yourself others have had issues when cut and shut into stock wiring. Normally you can get away with it when soldered in properly. Wire new wires in correct guage to come on when on full ignition (with time delay) and thats about as good as it gets for a side mount intercooler fan imo. Pressure switches etc are fine for something like a water injection system (theyre so cheap i suggest you invest in one, even a basic one works great) but not on an unmonitored a2a intercooler fan setup.
 
You don't want it to run stationary because its noisy? but you dont want heat soak either right? Sitting idling in traffic is probably the worst scenario when it comes to heat soak so forget not running it when stationary.
 
Don't get rid of your "better" fan if infact it is better.
 
The wiring parts for the fan should cost peanuts besides the labour to do it.
 
With dyno's it is hard but it only takes a phone call/conversation before hand to sort something out re:- fans.