Hardway Posted July 8, 2014 Share #1 Posted July 8, 2014 I have gone back to the stock style mechanical clutched fan on my 240z for now along with a MSA shroud that is on the way. My car had dual 10 or 12 inch cooling fans on it but the temp probe for the wiring kit would have required bending up some of the fins on my brand new Champion radiator and I did not want do that. I am wondering, can you use the original sending unit that is near the thermostat housing to also trigger a set of electric fans? Basically having 2 wires on it instead of the just 1 wire for the gauge in the dash? I have seen more advanced wiring kits that include a screw in temp sending unit but as of right now by engine only has the single sending unit for the dash gauge. I am asking because if I want to go back to electric fans I will know what is ahead of me. Thank you. Link to comment https://www.classiczcars.com/topic/49600-for-those-with-electric-cooling-fans-piggy-back-sending-unit/ Share on other sites More sharing options...
SteveJ Posted July 8, 2014 Share #2 Posted July 8, 2014 Not easily. The sending unit changes resistance according to temperature. The thermostat for the fans is more of an on/off switch. If you did manage to find a way, it would probably adversely affect the reading on the temperature gauge. Link to comment https://www.classiczcars.com/topic/49600-for-those-with-electric-cooling-fans-piggy-back-sending-unit/#findComment-451235 Share on other sites More sharing options...
Mike W Posted July 8, 2014 Share #3 Posted July 8, 2014 Jeff,I had the same issue when I went to electric fans and did not want to mangle my new radiator with either temp probes or the "through the core" tie wraps to hold on the fans.My solution to the temp probe turned out to be quite elegant and provided a great deal of programmability in terms of how the fans are actually used.I went with a Dakota Digital fan controller which you can find here:Electronic Fan Controller 70 AmpIt is an awesome product that lets you have complete control over fan turn on / off temp, running time after engine shuts off, etc. They also provide a temp sending unit that I ended up installing directly in the block of my Z engine. Turns out there is a fitting/plug (which I believe is there in order to drain the block of water if necessary) on the rear part of the block on the drivers side which I was able to remove and install the sending unit I purchased from Dakota. I recall that I had to find the right thread adapter to make this work, but it was very straight forward. I am not at my home at the moment so I can't get you the thread details, but if you need them I have them at my house. This gets wired directly into the Dakota controller so it will know the exact temp of the coolant within the block. This totally eliminated the need for the probes that go through the core of the radiator. I ended up mounting the controller in my glove box so it is accessible from the inside of the car. Turns out there are a few LED indicators on the controller and being able to see them while in the car can be useful at times. This turned out to be a very elegant solution, is completely reversible if desired, and brings some modern technology to an older style cooling system which gives you a lot more control.This unit, coupled with the radiator and fan mounting bracket that I purchased from Wizard Cooling along with high performance SPAL fans, has proven to be the most effective cooling system I have seen in a Z yet. I can be sitting in traffic in 100 + degree Austin weather and never go over half way on my temp gauge. In fact when the fans kick in (they sound like turbines by the way) you can actually watch the temp go down even while standing still. My old system never performed quite like this.Hope this helps. I'd be happy to show you what I've done if you ever decide to go back to the electric setup.Mike. Link to comment https://www.classiczcars.com/topic/49600-for-those-with-electric-cooling-fans-piggy-back-sending-unit/#findComment-451239 Share on other sites More sharing options...
Hardway Posted July 9, 2014 Author Share #4 Posted July 9, 2014 That is awesome Mike! Your Z truly gets the best of everything. I will look in to the Dakota module should I need to go that route. Knowing there is another temp sending unit location is the best piece of knowledge to have. Thank you for your detailed post. Link to comment https://www.classiczcars.com/topic/49600-for-those-with-electric-cooling-fans-piggy-back-sending-unit/#findComment-451256 Share on other sites More sharing options...
Walter Moore Posted July 9, 2014 Share #5 Posted July 9, 2014 I mounted a temperature switch in the heater line for the SUs. You have to buy a BSPT to NPT adapter nipple, and a T for the switch. But it seems to work well. I know that I bought the temperature switch from Summit Racing, but it was 3 years ago and I don't remember the part number. Link to comment https://www.classiczcars.com/topic/49600-for-those-with-electric-cooling-fans-piggy-back-sending-unit/#findComment-451259 Share on other sites More sharing options...
GRLS30-001855 Posted July 12, 2014 Share #6 Posted July 12, 2014 This is the controller I used and am very happy with. Straight forward installation. HPC Electronic Radiator Fan Controller Control Module with Sensor 102001 | eBay Link to comment https://www.classiczcars.com/topic/49600-for-those-with-electric-cooling-fans-piggy-back-sending-unit/#findComment-451449 Share on other sites More sharing options...
Yarb
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