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Cooling fan operation
MB - 28/2/03 at 09:17 PM

I'm using a Ford X-flow / radiator and am planning on using an electric cooling fan instead of the original constantly running fan on the front of the X-flow.... simple, but how do you make the fan come on when the engine is hot and off once it cools?

Is there some sort of thermo-operated switch I can get off a scrap car that would fit my setup?


scutter - 28/2/03 at 09:25 PM

Pardon my asking, but you have read the book?

It say that when you fit the Fiesta thermostat housing, fit a fiesta fan switch in the blanking hole(ford part No. 6144361).

Not being Nasty, but a copy of the book would help things along.

All the best Dan.


MB - 28/2/03 at 09:59 PM

Sorry, I should have given more information... I DO have a Fiasta thermostat housing with a "thing" on top with two electric terminals. Thing is if I run the engine and get it really hot whilst measuring the resistance between the terminals I just get a constant (high) resistance.

Its got a new thermostat so I know that hot water would flow past the sensor, but nothing happens...

I was just wondering if there is anything else I could use - I followed what the book said, but that doesn't always work... not for me anyway.


MB - 28/2/03 at 10:02 PM

Do I just need a new sensor?

Is is supposed to lower it's resistance and act as a switch for the fan, or am I missing the plot totally?

I had expected it to behave like a bi-metal strip...


stephen_gusterson - 28/2/03 at 11:24 PM

it is a bimetal strip.

you might not get it hot enougth.

put it in a saucepan and boil it.

then measure it with an ohm meter. I had similar problems. On my car I couldnt find a way of mounting it reliably in the system - im using a ford v6 - so I have just wired the fan to be on all the time.

its using what - 1/6 th of a horsepower of my 130? Basic mk1 fiestas had no switch - fan was always on too.

atb


steve


theconrodkid - 1/3/03 at 03:21 PM

sounds like the thermoswitch is nackered,if you bridge the 2 wires does your fan start?if so new switch


jonti - 1/3/03 at 08:01 PM

Pardon me for jumping on this bandwagon but Anyone know where this magic switch might be able to live on a pinto ?


theconrodkid - 1/3/03 at 08:05 PM

i put a peice of tube in the top hose and araldited a metro switch in the hole i cut,simple


jonti - 1/3/03 at 08:19 PM

quote:
Originally posted by theconrodkid
i put a peice of tube in the top hose and araldited a metro switch in the hole i cut,simple


Mmm yes tthanks.....I was thinking along those lines actually. If it worked for you then I'll press on with confidence...Cheers..JJ


theconrodkid - 1/3/03 at 08:35 PM

i have some stainless tube that is a precise fit for x flow top hose,ill measure it on monday if you want some i got miles of the stuff


stephen_gusterson - 2/3/03 at 12:12 PM

quote:
Originally posted by theconrodkid
i put a peice of tube in the top hose and araldited a metro switch in the hole i cut,simple


yeah, that might work, it might not.

yer might just have the alraldite give up on you cos of the heat and 15lbs pressure.

I tried to solder mine in place over a hole in a bit of tube.

I wriecked 2 switches that way!

I just reconed it was better to have no switch than a method I didnt consider reliable.

One entains a little fan noise which you can hardly hear, the other a lot of walking and inconvenience.....


atb


steve


chrisg - 2/3/03 at 02:29 PM

Or a switch on the dash and an eye on the temp guage.

Cheers

Chris


theconrodkid - 2/3/03 at 03:36 PM

Steve the araldite has held for a year so cant see a prob there


jonti - 2/3/03 at 04:13 PM

Actually the more I think about this the more I like Steve's method of leaving the fan on all the time. I quite like the idea of the fan whining up to speed just before I light the engine ( am I a sad b*st**d or what ??...50 going on 15 !!)
Thanks for the offer of the tube though conrod , you're a true gent. But I already have some ta


theconrodkid - 2/3/03 at 05:42 PM

ive been called a lot of things in my time but never a true gent,must be doing something right at last


stephen_gusterson - 2/3/03 at 10:32 PM

actually, the fan dont make that much noise when running, but you sure know its there before the key is turned. As I have a rad from a 2 litre car on a 2.4 litre engine, in a fairly tight space, I thought more cooling was better than less.

Conrod - sounds like it works - and I think there are also metal loaded epoxies - it just concerned me that boiling water and high pressure wasnt a safe combo, but perhaps its ok....

I was thinking of finding out what the thread was on the sender, getting a steel boss made and welding it to pipe.

leaving the switch out was so much faster and cheaper!


Many modern car rads have a switch in them.....if you can find one that fits thats the way to go.

atb

steve


[Edited on 2/3/03 by stephen_gusterson]


David Jenkins - 3/3/03 at 08:48 AM

As a matter of interest, what's a good temperature to cut in the fan?

DJ


david walker - 3/3/03 at 08:17 PM

Problem with the Fiesta switch in the thermostat housing could be that it isn't getting hot enough to cut in. I have a switch into the bottom hose (pipe with boss brazed in) and it only comes in when really, really hot. Originally had it in top hose, same problem, someone then told me to move it into bottom hose. No different!

I now have additional switch on dashboard and flick the fan on when hot, if I forget then the thermoswitch would come on - just prior to cooking motor! I have tried a couple of switches with same result.

Have thought about a Kenlowe switch with variable temp control, and may fit one this summer. I'd like to see the fan on at about 80deg C, rather than the 90+ that factory switches seem to activate at.


paulf - 3/3/03 at 10:17 PM

RS components sell a capillary type thermostat much like the kenlowe on for about £12.the probe can be inserted in the top or bottom hose as requred.

Paul.

quote:
Originally posted by david walker
Problem with the Fiesta switch in the thermostat housing could be that it isn't getting hot enough to cut in. I have a switch into the bottom hose (pipe with boss brazed in) and it only comes in when really, really hot. Originally had it in top hose, same problem, someone then told me to move it into bottom hose. No different!

I now have additional switch on dashboard and flick the fan on when hot, if I forget then the thermoswitch would come on - just prior to cooking motor! I have tried a couple of switches with same result.

Have thought about a Kenlowe switch with variable temp control, and may fit one this summer. I'd like to see the fan on at about 80deg C, rather than the 90+ that factory switches seem to activate at.


stephen_gusterson - 3/3/03 at 10:32 PM

the original switch for the fiesta mounts above the thremostat as the top hose comes in to the stat housing. I guess if you put it there it will work fine.

The RS thing, if its the one im thinking of, has a capiliary tube with a copper pencil shaped cylinder about 70mm long at the end. Its adjustable and has a copper capiliary to the adjuster.

I got one of these but decided against it cos there is the problem of getting it into the pipe without it leaking such that the whole body of the sensing bulb is in water, and the control knob is basically a skeletal switch that needs mounting in something.

Not sure of the switch rating, but it would need a relay if its not in the region of 10 amps.

I had one of these, and thougt the hassle wasnt worth it. But it is a possible solution if you want an adjustable control if you can get it fitted without crushing the capiliary under something like a jubilee clip.

atb


steve

[Edited on 3/3/03 by stephen_gusterson]


david walker - 4/3/03 at 09:18 PM

Steve, you're probably right about the Fiesta switch in that if mounted in the thermostat housing it would probably work ok. I haven't been able to use that housing because of the (common) underbonnet clearance problem.

The switch works ok on the Fiesta/Escort but I think I'm looking for a bit of air movement at less than 90deg. These cars get very hot under the bonnet and a fan coming on earlier appeals - hence my manual over-ride.

As for the thermocouple that Paul describes, it sounds just like the Kenlowe one - but at better price. If it needs to go through a relay then OK. As for the fixing within the hose, this is exactly how Kenlowe do it - push it into hose and tighten all up with big jubilee clip!


stephen_gusterson - 4/3/03 at 10:09 PM

if that works thats great.............just looked to me that the pipe might get squished! obviously its ok


rs 561-460

12.49p

atb

steve Rescued attachment switch.jpg
Rescued attachment switch.jpg


paulf - 4/3/03 at 10:22 PM

Thats the exact one Steve ,I was looking at one at work today. I have a kenlowe one on my MGB and it is virtually identical, it can be mounted on a small bracket and a small piece of rubber put between the capillary and hose allows the hose and jubille clip to be secure with no leaks and no danger of crushing the capillary. The one on my MG has lasted 20 years so far with no problems.
Paul.

quote:
Originally posted by stephen_gusterson
if that works thats great.............just looked to me that the pipe might get squished! obviously its ok


rs 561-460

12.49p

atb

steve


GO - 6/3/03 at 11:43 AM

I had a kenlowe switch like that in my old TR. Worked perfectly, and being able to adjust the cut in temp is v.handy.

I didn't fit a relay, the kenlowe instructions didn't mention the need although the fan was rated at 30amps.

As Paul says above, with the kenlowe kit you get a piece of rubber, about an inch square that fits in the end of the hose under the jubilee clip. It had a grove along the centre which the sensor tube fits it to prevent it getting crushed. Blimin fiddly to fit when the hose is already a snug fit over the rad outlet without the extra thickness of the rubber. Took me a week or so to get it just right to prevent leaks, trick is to tighten the jubilee once the engine is up to temp and the hose is soft.


sg_frost - 17/3/03 at 01:33 AM

quote:

Pardon me for jumping on this bandwagon but Anyone know where this magic switch might be able to live on a pinto ?



Seem to remember most pintos having a viscous fan, not electric. Anyone know of a pinto with a electric fan???


jonti - 17/3/03 at 12:38 PM

They do have a viscous fan..that's why I asked where the switch "might be able to live" in order to switch on the OEM fan that I have. Cos there isn't a Ford hole for a switch to go in.......... Do pay attention class !!!


david walker - 17/3/03 at 09:25 PM

Jonti, you'll have to put one in line with top hose using one of the tee adaptors described earlier. That' what I have, but as I've said they don't really come on until the whole thing is very hot. I suggest you explore the Kenlowe type switch described by Steve.

I'll be fitting one of these when I get around to it!