X Eng Fan Switch

[MudRat]

Does it fit on the top or bottom hose from the rad, it says the bottom, can it be fitted to the top? Has anyone fitted it there?

[Disco-Ron]

The reason it says fir it in the bottom hose is that the water goes in the bottom of the rad, and out of the top, therefore the water is hotter at the bottom hose..... if you fit it in the top hose, expect the motor to runa  bit warmer than it otherwsie would.....

[Range Rover Blues]

Nah, hot water out of the top of the negine and cold back in at the bottom, so you get a "gravity" feed without the fan.  The switch X-Eng use is notmaly screwed halfway up the rad, so if it's sat in the bottom hose then you will run quite hot before it switches on, if you fit in the top (where I thought I'd seen one fitted) it might run cooler.

TBH as long as it's not on when you are moving normally I'd fit it to the top, overheating is very bad for a V8 as it leads to main journal fretting as well as cracked block problems, I'd say the same for a TDi TBH.

If it comes on when towing, that's another matter.

Personally I used one of Wizard's adjustable 'stats (not an offroader) and set it so it comes on when sat in traffic but goes off when I'm moving and on Blue I fitted a Merlin Motorsport one about halfway up the rad core, adjust the temp setting by moving it up or down the rad.  The downside is that one hates getting wet so I might swap it for a Wizard one.

[tack43]

It does state in the instructions to fit it in the bottom hose!  :-k www.x-eng.co.uk/X-fan.asp and click on "See fitting" Personally I would use the "hotter" sensor and fit it in the top hose.

[L90OOK]

It's fitted into the bottom hose so only switches fan on when radiator fails to cool water sufficiently.  Fitting it to the top hose will mean the fan will be on when may not be needed therefore you may as well go back to a viscous fan  :roll:
Mines fitted to the bottom hose & is wired through a off-on-oncarling switch removing the need for a relay. 
I have it wired for automatic fan on at the lower temp,constant on or isolated. 

[zulublue]

I am so glad I have found this thread, I have had a X thermostat fitted for about 10 months now, its on a D90 200 TDi, I fitted it to the output side of the rad for the reasons L90ook said, It is set on the lower temp side of the thermostat, but it has never clicked in either in the hottest day in summer of off roading, I have wired the switch directly to the fan to test and it works fine, but it seems that the engine never gets hot enough.
My temp gauge does sit right over on the white bit before the black and the red and never moves, the engine is a Disco block with my original defender casings etc all I used was the cast block itself, I have wondered if I have wired it wrong, but Simon at X-Eng says my diagram is fine. I can touch the output side of the rad with my hand so I guess it's doing it's job.

It's now at the point that I will direct wire it to a switch, and keep an eye out don't know what else I can do really.

[dazzawhipple]

On my old V8 i fitted it to the top of the rad


Darren

PS Merry christmas .........

[V8MoneyPit]

Their recommendation to put it in the bottom hose surprises me. As RRC says the hot water leaves the thermostat (when open) and into the top of the rad. The cooled water is then pumped back into the block from the bottom.

If the engine begins to get too hot, the thermostat remains open all the time, so I would expect to measure the temp at that point to determine when to switch the fan on.

But I guess fitting it in the bottom hose is fine as long as the switch/sensor is rated a lot lower because the water has already been cooled.