Adding a electric fan sensor switch

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Tigerfan
Posts: 66
Joined: Tue May 05, 2009 4:46 pm

Adding a electric fan sensor switch

Post by Tigerfan » Sat Jun 10, 2023 12:01 pm

Hi Guys,
With the summers getting warmer, I only have a manual fan switch on my Tiger so it's time to fit a temperature sensor to bring the fan on automatically.
Question: There are 'T' adapters with a 22mm threaded port for the sensor on e-bay which would fit, but where to put it, top hose?
I'm sure plenty of Tigers have such an upgrade. Any info is appreciated.
Thanks
Rich

garyf
Posts: 238
Joined: Tue Jan 16, 2018 2:14 pm

Re: Adding a electric fan sensor switch

Post by garyf » Wed Jun 14, 2023 2:07 pm

Hi Rich

I have a manual switch to control the additional 11" SPAL Fan fitted to my car, so I can't confirm what is the best location.

Your suggestion of on the top hose makes sense to me as that will be the water at its hottest travelling into the Radiator.

My car has a short Stainless steel pipe section with two hoses linking between the Engine and the Radiator, you can probably buy this section of pipe with the 22mm threaded boss to accept the switch already fitted off one of the American Mustang specialists, Real Steel, Etc?

Cheers

Gary

Tigerfan
Posts: 66
Joined: Tue May 05, 2009 4:46 pm

Re: Adding a electric fan sensor switch

Post by Tigerfan » Sat Jun 17, 2023 7:21 am

Thanks Gary,
I have just fitted a Revotec sensor in the top hose which is similar to what you've suggested. Rich

Tigerfan
Posts: 66
Joined: Tue May 05, 2009 4:46 pm

Re: Adding a electric fan sensor switch

Post by Tigerfan » Sat Jun 17, 2023 1:27 pm

Hi Guys,

Having part drained my cooling system down to remove and check Thermostat function as even though with the engine running and seemingly reaching operating temperature, the top hose seemed to be void of water when sqeezed. The fan sensor is coming on before the hose is filled with water when thermostat should open just by the temperature of the empty hose. The water is approximately 1/2 way up the reservoir tank but overflows through the pipe beneath the cap when engine is running? cap is is the correct 13psi.

The Thermostat seems to open when checked in hot water on the stove, so is probably OK.

I'm not sure why after 8 years of use though I seem to have this problem. Possibly air in the system. All hoses have been checked and appear OK. I will replace the Thermostat anyway, but is there any particular procedure with a Tiger that should be used to avoid adding air/purging air when refilling.

Thanks
Rich

garyf
Posts: 238
Joined: Tue Jan 16, 2018 2:14 pm

Re: Adding a electric fan sensor switch

Post by garyf » Mon Jun 26, 2023 1:58 pm

Hi Rich

I recently replaced my Heater Matrix and didn't have any trouble with Air Locks on re-filling and re-starting my car.

Did you keep the Heater Valve open when running the Engine up to temperature?

I made sure the Matrix was nearly full of coolant and half filled the Header tank before restarting and warming the car up.

I then had to top up very slightly the Header tank once again.

I've connected up the overflow pipe off my header tank to a small 250ml bottle designed for a motorcycle and I keep this half full too (You can just make it out in this photo in the top right).

Gary
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nicam
Posts: 21
Joined: Tue Aug 06, 2013 11:37 am

Re: Adding a electric fan sensor switch

Post by nicam » Fri Sep 01, 2023 10:45 am

I have always followed convention when fitting a temperature sensor for a fan and fitted it in or around the top hose, but have often wondered (sad, I know) if this is the wrong place.
When the water in the top hose is at "run fan" temperature, this means that the engine is already over its optimum temperature i.e. the water coming out of the engine is hotter than "normal".
Assuming that the cause of this is idling and a lack of forward movement, as opposed to the engine working hard, then it seems logical that having a sensor in the bottom hose would be more sensible as it would detect that the radiator was unable to cool the water passing through it due to a lack of natural air flow, and the fan could be energised earlier to allow the radiator to do its job and for the flow of water into the engine being cooled, allowing it to do its job, controlling the heat build up in the engine.
I have never actually used this as a system, but would be interested for comments as to the logic of the argument! I may have missed something important and wouldn`t like to cook an engine if I have! Thoughts?

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