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Radiator Fan Advice please
karlak - 3/8/13 at 08:16 AM

The MK Indy was built with a manual switch for the Radiator Fan. This is on the Dashboard and simply allows me to turn the fan on and off.

I never got round to putting in a temp switch as the previous radiator didn't allow for it, but now the car has had a pretty big overhaul, I could now run the Fan when required using the Omex 600.

I have a Relay so I can use the "sense" wire from the Omex, but am just wondering whether it may be worth keeping the manual switch in place as well ? Or if that is even possible. Would it be worth just removing the manual switch wiring altogether and let the Omex do its thing ?

Any advice or guidance? A little wiring diagram suggestion would be handy as well. Something I must do today is chase the manual switch wiring, because I am not sure how that has been wired in.

Davey D - 3/8/13 at 09:12 AM

Mine comes in either by the thermo switch in the radiator, or by a manual switch. Normally the fan will be controlled by a relay which is switched by your manual switch. All you will need to do is run another set of wires from your thermo sensor to the relay to make it switch on

adithorp - 3/8/13 at 10:18 AM

Having it switched by the ECU or a thermo' switch in the rad is preferable. Then you can't fail to spot the temp rising and not switch the fan on.

I'd still keep the manual switch though. That gives you the option to switch it on at times when heat soak could cause temps to rise rapidly. I use mine when finishing a session on track or stopping to look at the view after blatting up a mountain.

40inches - 3/8/13 at 02:58 PM

quote:
Originally posted by adithorp
Having it switched by the ECU or a thermo' switch in the rad is preferable. Then you can't fail to spot the temp rising and not switch the fan on.

I'd still keep the manual switch though. That gives you the option to switch it on at times when heat soak could cause temps to rise rapidly. I use mine when finishing a session on track or stopping to look at the view after blatting up a mountain.


Heat soak can be a PITA, although the ZX9 switches the fan on for 30 secs after the ignition is turned off, if the engine is hot, I
assume this is built into the ECU?

Worzey - 4/8/13 at 06:29 AM

Did a recent upgrade on mine and ended up with an Omex 600. I replaced the manual switch and now let the Omex do the work for me. I believe the Omex 600 has a secondary fan wire for engine bay fans. If heat soak is an issue you can use this to remove heat but i found cutting a hole in the side panel was just as effective.

I had problems with the manual fan....biggest issue was when the local MOT station left the engine running while checking the emission levels and lights. Dumped the contents of the rad all over the garage floor. I should have turned the fan on before i left them the keys.

karlak - 4/8/13 at 07:04 AM

Thanks Guys,

I will check the wiring on the manual switch and decide which way to go from there.

snowy2 - 4/8/13 at 05:54 PM

search my article on here "how to rewire your car the easy way" it includes a separate article on fitting an over ride switch even if using a relay on the fan.

Scuzzle - 4/8/13 at 06:40 PM

I run my fan off the Davis Craig Electric Water Pump Controller which is a smart bit of kit, fan comes on at 5 deg after whatever temp I set the cooling system to, if the engine is at or above temp when I switch the car off the water pump and fan run on for 2 minutes to give it a nice even cool down.