Electric Rad Fan Fitting

[Guest]

No, Iain.

The override switch is just that, it will keep the fan on until you manually flick the switch off.

The rationale for having an override switch on the dash is that if you see traffic building up and you will be crawling along, you can get the fan running before it automatically cuts in. It helps to pre-empt keeping the cooling system at a manageable level rather than the fan cutting in and having to bring the temperature down from that higher level which entails greater work.

If you want your fan to run on after the engine has been switched off, you need to connect the wire on relay point 86 to a NON switched ignition live terminal. I should point out that the fan will only turn itself on if it needs to do so. 

Regards.

Richard.

 

[Iain T]

Richard, just re read your posts are you saying not to connect the controller yellow ignition wire to the cars switched live? I would rather not but don't know if the widget will work if the yellow wire is not connected. 

[Guest]

Personally, I'd connect the installation as per the instruction to begin with; to ensure everything is working as it should. From there you can adjust to suit your requirements.

Regards.

Richard.

[Iain T]

Mmm yes deviate at my peril. 

Thanks everyone for your help, I'll report back. 

Iain 

[Peter Truman]

Don't know about Davies Craig controller but the normal Elect Fan Conversion using a simple relay (see Richards post) we found when wiring up the Spit fan;

• A manual control illuminated switch didn't work ie lite up when 'switched on' except at the instant of turning it on and off, a separate light as per Richards diagram had to be fitted powering off the battery feed to the fan relay 87.
• Power to the fan is controlled by the relay which is activated by the ignition supply 86 so when the ignition supply is turned off the relay deactivates and the fan will stop as the battery supply to the relay is broken, ie the latched battery supply 30 thro 87 is broken.

We brought a cheap $20 kit locally supplied here, which included the fused relay, thermo switch (3/8in NPT), 3/8in NPT to 3/8in BSP brass adapter, good length of various coloured and gauge wiring, connectors, and thermal cut out, we had to supply the manual over ride switch. hey it works great I've subsequently brought a range of Thermo Switch's around $4 ea ex Hong Kong so the daughter can experiment which she wants, I pulled one to bits its all brass and its well made, I also glued (JB Weld) a second blade fuse holder onto the relay integral blade fuse so both the battery and ignition supplies to the relay were fused. 

Re the D-Craig controller our club members have installed them on the parcel shelf and in the glove box where they can play with the controls/settings.

[Steve P]

18 hours ago, classiclife said:

No problem.

Originally I wired my fans so that they cut out when the ignition was switched off. That has changed and they carry on running until they have done their cooling requirement with the engine switched off.

As to wires, I use Thinwall cable.

Regards.

Richard.

My Spal on the Vitesse is wired to keep going after the engine is turned off,when i put it in the garage the fan normally runs for a couple of minutes if it`s been idling.

Steve

[Guest]

17 minutes ago, Steve P said:

My Spal on the Vitesse is wired to keep going after the engine is turned off,when i put it in the garage the fan normally runs for a couple of minutes if it`s been idling.

Steve

Ditto for me Steve and I tend to open the bonnet to assist getting rid of the hot air - found it makes a helpful difference to the fan running time.

Regards.

Richard.

[rlubikey]

Belt and braces, you can get timing relays (e.g. for heated rear windows) so your fan will run until the temperature sender says it's cooled down, but for a maximum of, say, 10 minutes after ignition off (timer).

Cheers, Richard

[Iain T]

On soldering iron duty now, unfortunately my wife had a work schedule for me today that differed from mine and compliance was obligatory! 

Of course if you want full control of the engine coolant an electric water pump and fan is the way to go but a bit too far from originality... 

Iain 

[Iain T]

Ok it's wired in albeit not expertly as I wanted to know if it works and does it's job before making it look presentable.

The manual override works but only when the ignition is turned on so the green AC cable does not override the yellow Ignition? I have the toggle switch wired in to a fuse box straight from the battery so it's always live as I thought this stood a chance of working when the ignition is off but it no. For the moment not a great problem. 

I had a 'moment' on the first run as the car temp gauge was all over the place (up to 100C) so I came back, run the car up on front ramps and let the engine cool down. I then took the rad cap off, started the engine and opened the heater valve. The coolant went down (more than a pint) so I topped it up and ran the car up and down the car park (7 storeys) and all seems to be stable. 

I'll take it out for another run this week to see if its ok in traffic.

However somehow I seem to have lost power to my AFR meter...???? The wires are all in there I just need to connect them correctly!!!

Another plus for dumping the crank fan is the engine is as smooth as silk. It was smoother after the engine rebuild but the yellow fan must have been way out of balance or the mounting rubbers were shot.

Iain

[Iain T]

Update, the Spal standard 11" fan isn't up to the job on hot days and traffic. I have a 12" uprated Spal arriving tomorrow with 50% more suck, I just hope it fits! It's the same rime depth but will need some juggling to get in. 

Iain 

[PeteH]

May I just observe. Many (if not most) modern cars with Electric cooling fan`s have (plastic) shrouding. The object of which (it is said) is to direct the air through and across the whole of the matrix and not just a part, thereby with improved cooling effect?.

I recently disposed of a Fiat Punto (16V pocket rocket) which was fitted with shrouded twin thermostatic cooling fans.

[Iain T]

Shrouds are commonly used on modern cars to funnel airflow through the rad and do work. 

I have yet to try fitting the uprated Spal, it looks extremely tight!! 

Iain 

[Clive]

On 24/08/2020 at 16:57, Iain T said:

Ok it's wired in albeit not expertly as I wanted to know if it works and does it's job before making it look presentable.

The manual override works but only when the ignition is turned on so the green AC cable does not override the yellow Ignition? I have the toggle switch wired in to a fuse box straight from the battery so it's always live as I thought this stood a chance of working when the ignition is off but it no. For the moment not a great problem. 

I had a 'moment' on the first run as the car temp gauge was all over the place (up to 100C) so I came back, run the car up on front ramps and let the engine cool down. I then took the rad cap off, started the engine and opened the heater valve. The coolant went down (more than a pint) so I topped it up and ran the car up and down the car park (7 storeys) and all seems to be stable. 

I'll take it out for another run this week to see if its ok in traffic.

However somehow I seem to have lost power to my AFR meter...???? The wires are all in there I just need to connect them correctly!!!

Another plus for dumping the crank fan is the engine is as smooth as silk. It was smoother after the engine rebuild but the yellow fan must have been way out of balance or the mounting rubbers were shot.

Iain

I am really surprised. I have that very 11" fan, and the temp drops like it is falling off a cliff when it kicks in. Mind you, modern ali radiator with a shroud, so that may improve fan efficiency.

[Iain T]

I think a lack of oil pressure may have contributed to the temperature. Now that's been fixed I'll keep with this fan for now and test the rad to see if I have any cold spots. 

Iain