Dual thermo fans

[Old_Mt_Isa_Boy]

Have finally solved the engine overheating issues. As part of the solution I have connected a pushing and a pulling fan. I also have a Davies Craig electric water pump and controller under the dash. Have an aircon as well hooked up to the grey.

My concern is I have the 2 fans connected via a piggy back to the controller. I imagine the controller has a single relay.

Do I simply hook up a second dual relay in the engine bay and hook both fans up to that and then on to the existing relay within the controller. I know I could take a chance on the bogie piggy back but it looks like crap. Any help would be appreciated.

Another idea is to accept that one relay is sufficient and modify a twin deutsch plug and bridge across two terminals from one input. At least that would look the part ( don't know how to do that by the way)

Regards

Wayne b

[FCRB26]

2 fans seems overkill to me but then again its not my car getting hot

is your fan stepped off the core or bolted straight to it ?

send me a picture or post a pic of what you have .

Pete

[Old_Mt_Isa_Boy]

Pushing fan attached to aircon condenser



Pulling fan hooked up to rear of radiator



Originally had a Spal fan however would not fit between radiator and pump. Had a alloy shroud as well. Wasn't meant to be. This was the skinniest fan I could find. 

Messy piggy back connectors.

[john253a]

I like to you the controller to control a second relay with does both
Fans
I also fitted a on/off/on (3 posion) switch in line from the controller to the relay
And put a led light on the out wire

That way I can either run the fans through the controler as designed to or turn them straight on if I no I'm in heavy trafic or being stuiped
The led is so I know when they are on

[hsv-001]

Wayne, I was talking to my local air con guy and he said that the condenser should be as close as possible to the core and I presume that's what Pete was getting at . From memory yours is .It forces the air to travel through both sets of fins without losing direction .Your sender unit should be an earth and if the controller has a relay inside then one of the wires that goes from the controller to the fans should be the power supply.This power supply can be the switch wire to a single relay with dual outlets to both fans . Anyway I'll give you a call before Christmas . Haydn

[Old_Mt_Isa_Boy]

Have both fans hooked up to a relay and at the same time hooked the positive air con up to the fans as well through another relay. If the aircon comes on fans on otherwise fans run by thermostat control and the Davies Craig black box. Overall a good result I think. I would have prepared for this if I had known the issue.

Thanks for the input. John liked your idea of an idiot light and separate toggle switch but the Davies Craig black box has a series of lights indicating the system is working.

Regards

Wayne b

[NES304]

Wow, funny this thread came up, I was actually SMS ing Pete minutes prior to this. I have very limited room between my radiator and my belts, pulleys etc.
I have opted for the Davies Craig fans because they are 51mm thick as opposed to the Calibre brand that are 88mm thick and Davies flow more air too!
I have cheated though and have the fans on the original VT relays (including the one running off the Aircon switch).....

[john253a]

I wouldn't call that cheating, more along the lines of less work and smarter thinking

[hsv-001]

I have had a dial up thermostat on my v6 for a long time . When I was installing v6's I found that they were set up to run quite hot with water pressure high to stop them boiling . I could list the specs but it is better to just use a cooler thermostat and sender and a fail safe dial up to over ride the computer .Finally I have a light up three position  toggle switch on the dash that will light when the fan is activated .And so display when activated by the computer or the dial up or when I turn the fan on manually . At first I was concerned that this system may trip a sensor that would run the engine too rich [choke setting] or effect other areas such as the transmission change into overdrive, but I have had no problems with the set up in 4 years . I use lots of components from donor vehicles and it is not cheating ,its a financial necessity but I like to understand how they work when I install them . Its just what I enjoy. Anyway Wayne the way you have documented each step [and problem] of your resto should guide and inspire others .Cheers Haydn