Fitting Digital Thermo fan switch to DS

Glenn Drake

Glenn Drake

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I am always willing to have a go and learn from my mistakes…unless of course I can first learn from others mistakes…😊
I have decided to fit a Davies Craig digital thermo fan switch to my DS23.
I want to replace the existing thermo switch in the radiator with the digital one so I can adjust the temperature that the fan comes in. I am looking to use the temp probe in the radiator core that measures air/radiator temp rather than the water temp option.
The DC digital also allows me to run an additional fan, which may come in handy now I have mounted an aircon condenser in front of my radiator. The two fans can even come on at different timings which sounds pretty neat!

So, question is, is there anybody else out there that has done this/similar to their classic?

Advice and opinions graciously accepted👍
 
This looks like the kit you are talking about. https://daviescraig.com.au/product/digital-thermatic-fan-switch-12v-24v-0444

The hardest part of the installation that I can see is installing the sensor. I'm guessing that your current thermo switch will be metric. The NPT adaptor that Davies Craig sell looks like a thermo well and will not be suitable for you. You will need to find yourself a suitable adaptor that screws in place of the standard sensor and that will also hold the Davies Craig sensor.

So first thing to do is work out what the standard sensor thread is. It maybe written on the sensor itself what the thread is along with the temp that it switches at.

As for the wiring it should be straight forward, just follow the instructions in the kit.
 
COL I am planning just to use the air temp probe that is inserted into the radiator core (between the radiator fins), as I am pretty sure the water temp sensor will not fit the DS.
You can of course get the kit that you retrofit into a radiator hose, but this looks a little problematic to me.
 
I
Glenn Drake said:
I am always willing to have a go and learn from my mistakes…unless of course I can first learn from others mistakes…😊
I have decided to fit a Davies Craig digital thermo fan switch to my DS23.
I want to replace the existing thermo switch in the radiator with the digital one so I can adjust the temperature that the fan comes in. I am looking to use the temp probe in the radiator core that measures air/radiator temp rather than the water temp option.
The DC digital also allows me to run an additional fan, which may come in handy now I have mounted an aircon condenser in front of my radiator. The two fans can even come on at different timings which sounds pretty neat!

So, question is, is there anybody else out there that has done this/similar to their classic?

Advice and opinions graciously accepted👍
Click to expand...
I have a 1965 351 F250 that soley cools off a 16" thermo fan. It does have a 10" one on the aircon condensor but it is wired to only be on whenever the AC is on.

I bought an aluminium sensor adaptor that fits in the top hose. It does mean you have to cut the hose in half to fit it, but you can fit any sensors you like into it. I fitted it about 4 years ago and it has performed faultlessly

Davies Craig make these too for around $45, I bought a cheaper one off EBay for $15, similar to the DC one in the image. Mine came with two threaded holes in it but as you can see you could drill and tap more into it if you wished.
 

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Glenn Drake said:
COL I am planning just to use the air temp probe that is inserted into the radiator core (between the radiator fins), as I am pretty sure the water temp sensor will not fit the DS.
You can of course get the kit that you retrofit into a radiator hose, but this looks a little problematic to me.
Click to expand...
You will find that the system will work better with the temp sensor in the coolant. The radiator fin option will give you slight delay and also the temp won't be as accurate. Just my :2cents: worth.
 
Glen. This is a project I want to do as well but adding the electric water pump option so the fan and the pump work together. No more thermostat! Let me know how you go
Glenn Drake said:
I am always willing to have a go and learn from my mistakes…unless of course I can first learn from others mistakes…😊
I have decided to fit a Davies Craig digital thermo fan switch to my DS23.
I want to replace the existing thermo switch in the radiator with the digital one so I can adjust the temperature that the fan comes in. I am looking to use the temp probe in the radiator core that measures air/radiator temp rather than the water temp option.
The DC digital also allows me to run an additional fan, which may come in handy now I have mounted an aircon condenser in front of my radiator. The two fans can even come on at different timings which sounds pretty neat!

So, question is, is there anybody else out there that has done this/similar to their classic?

Advice and opinions graciously accepted👍
Click to expand...
ct I wanted to do but with the combined water pump option.
 
Can anyone tell me why I don’t show as a subscriber. Paid up but no mention
 
I used a different solution to operate a DS electric fan.
An electronic temperature guage using a simple external engine temperature sensor will not only activate a fan relay, at a custom setting, but also sound an alarm if a higher temp is reached. I had a unit which also beeped when operating temp was reached, maybe a reminder to open the choke! You have also a digital temp reading, maybe tastefully hidden below the dashboard.
The temp sensor can be bolted to the head, no need to penetrate the cooling system. (A radiator mounted sensor will indicate cool if all the coolant is gone!)

This is a similar unit to the one I used:

https://www.ebay.com.au/itm/112652870928?hash=item1a3aa26510:g:3IoAAMXQnYJQ9pAS
 
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Speedflow sell metric to NPT adaptors. I can't see that being an issue for using the correct sensor in the coolant.
 
Hi :)
What is a digital switch for a thermo fan, ON- OFF ??;)
Just being sarky ! It all sounds like a good idea but really more electronics controlling a vital function has often proved to be more trouble IMHO and the old reliable methods are tried and proven over the years. :D
Jaahn
 
I seem to remember a longish thread on here about fitting electric water pumps, electric fan, removing the engine driven fan and extra sensors. All Davies Craig. The conclusion was that it was a waste of time and reverted to original.
 
jaahn said:
Hi :)
What is a digital switch for a thermo fan, ON- OFF ??;)
Just being sarky ! It all sounds like a good idea but really more electronics controlling a vital function has often proved to be more trouble IMHO and the old reliable methods are tried and proven over the years. :D
Jaahn
Click to expand...
I must disagree with you ... the temperature gauge fitted ( IF fitted at all ) is like the fuel gauge ie a wildly inaccurate device.
Both are not to be trusted.
These modern fans and switches offer a real insight and a good reliable indicator of what is happening, and after the investment to keep a lovely DS in working shape ( or better than new ) the installation of a new gadget seems a minimal further expenditure and effort. A good insurance policy.
 
jaahn said:
Hi :)
What is a digital switch for a thermo fan, ON- OFF ??;)
Just being sarky ! It all sounds like a good idea but really more electronics controlling a vital function has often proved to be more trouble IMHO and the old reliable methods are tried and proven over the years. :D
Jaahn
Click to expand...
You may be right, just a warning light and a switch might work, but there is a reason they are know as "idiot lights"... They tend to inform you that the horse has already bolted.
As mentioned, the original temp gauge is unreliable, not least because it measures coolant temp, not engine. 5 litres of coolant on the road will quickly cool!

A combination of an immediate digital readout, loud alarm and auto fan switching makes sense to me.
Note, the electric fan fitted as original equipment to the DS23 was auto operated by a thermo switch responding to coolant temp.
 
badabec said:
I seem to remember a longish thread on here about fitting electric water pumps, electric fan, removing the engine driven fan and extra sensors. All Davies Craig. The conclusion was that it was a waste of time and reverted to original.
Click to expand...
Disagree. Davies craig have been around most of my life and their product is good. You get an immediate reduction in engine noise (no fan running hard as you rev) and a measured increase in power that is used by both the fan and the water pump. There is a reason modern cars do it this way
 
PeterMol said:
Disagree. Davies craig have been around most of my life and their product is good. You get an immediate reduction in engine noise (no fan running hard as you rev) and a measured increase in power that is used by both the fan and the water pump. There is a reason modern cars do it this way
Click to expand...
Hmm Yes there is a reason and I suspect it is not what you think. I do not know of any car with an electric water pump ? With sideways engines having a fan on one end is awkward for the radiator position.
I do not deny modern things and ways of doing it might be an improvement sometimes but if the temp gauge is the problem then fix that, not everything around it. I always thought Davis Craig had expensive solutions for problems no-one had. Just an old tight arse really:oops:
But it is your car and you may choose to do with it what you like. Go for it and stimulate the economy.
cheers jaahn
 
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