oldschool2 Posted August 2, 2009 Share Posted August 2, 2009 (edited) Anyone have actual photos or good diagrams of the correct wiring connections for a Non-Turbo (NA) 280zx FI Auxiliary Cooling Fan? Also, what tells the fan to turn on at 216 degrees? Is the fan motor connected to a temp sensor, or is there a built-in temp sensor within the fan motor mechanism (BiMetal) ? The Haynes Manual is not very helpful. I guess the timer assy is under the interior glove box. Does the "extension duct" that pulls cooler (?) air from below help. I have read that the Turbo ZX cars had the extender duct that attached to the fan intake. My fan motor does not have the extended ducting, therefore the question. Thanks Edited August 3, 2009 by oldschool2 Attach Photo of Fan Extension Quote Link to comment Share on other sites More sharing options...
woldson Posted August 3, 2009 Share Posted August 3, 2009 Is this something you really need? Quote Link to comment Share on other sites More sharing options...
oldschool2 Posted August 3, 2009 Author Share Posted August 3, 2009 Thanks for the question: Yes I do! Reason; 115 degree days (in the shade). 150+ degree pavement. Black car. Engine bay over 200 degrees. All this equals heat soak. Although it is doubtful that the Aux Fan will help in OEM form, I am interested in modifying the Aux Fan to draw in cool air from the front of the car (maybe). Before I do anything I am trying to understand how the Aux Fan works in stock configuration. Further research indicates that the fan is triggered by a single wire sensor coming from the thermostat housing (near thermo time switch). I see a single wire in the vacinity of the thermostat housing, but am not sure as it does not look green as I have read in some posts. Quote Link to comment Share on other sites More sharing options...
woldson Posted August 4, 2009 Share Posted August 4, 2009 Yep. Good job searching;) Quote Link to comment Share on other sites More sharing options...
PurePontiacKid Posted August 4, 2009 Share Posted August 4, 2009 lol, I took the auxillary fan off of my car with no problem... and I live in Vegas, too... lol Quote Link to comment Share on other sites More sharing options...
oldschool2 Posted August 5, 2009 Author Share Posted August 5, 2009 Well, LOL all you want! Facts are that heat soak is a real and common problem with the Zcars. Nissan added the Aux Fan for a reason. The repair manual even mentions Vapor Lock. Yes I have read all the comments about Vapor Lock not affecting FI cars. Call it Vapor Lock or Heat Soak the symptoms are the same. There is no telling what mods may have been made to your car. If it is stock then you are lucky. I am trying to get info for a mod I plan to make to the Aux Fan. The Aux Fan does not help with heat soak in my experience. That is why I am thinking of making mods to the Aux Fan. Also, I see no problem with trying to understand how a system works. Quote Link to comment Share on other sites More sharing options...
PurePontiacKid Posted August 5, 2009 Share Posted August 5, 2009 Well, on my car, the only wiring connections it had were two bullet connectors, but I've never traced where they go exactly... Quote Link to comment Share on other sites More sharing options...
woldson Posted August 5, 2009 Share Posted August 5, 2009 Well, LOL all you want! Facts are that heat soak is a real and common problem with the Zcars. Nissan added the Aux Fan for a reason. The repair manual even mentions Vapor Lock. Yes I have read all the comments about Vapor Lock not affecting FI cars. Call it Vapor Lock or Heat Soak the symptoms are the same. There is no telling what mods may have been made to your car. If it is stock then you are lucky. I am trying to get info for a mod I plan to make to the Aux Fan. The Aux Fan does not help with heat soak in my experience. That is why I am thinking of making mods to the Aux Fan. Also, I see no problem with trying to understand how a system works. Whoa there, it did not seem to me that he was really mocking/slamming you. With his next post, he definity seemed to not be what you were thinking. Being part of HybridZ, you need to develop a little thicker skin. I hope you have good luck in modding the injection cooling fan system, post pics! Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 5, 2009 Share Posted August 5, 2009 Anyone have actual photos or good diagrams of the correct wiring connections for a Non-Turbo (NA) 280zx FI Auxiliary Cooling Fan? You'll have to excuse the folks spend 98% of there posts only saying "search". There are some on-line manuals here: http://xenons130.com/reference.html Basically the fan is "dumb" and only has 2 bullet connector wires to connect it to the harness. No, the fan is not so much for cooling the rail as PREVENTING heat from the exhaust from rising up and getting to the rail in the first place. As long as it puts a stream of air between the manifold and the rail so rising heat is deflected away from the rail, it works. The "extension" might have been added just for the turbo so it won't suck up really hot air coming around the engine from the turbo housing; the non-turbo won't need that. Quote Link to comment Share on other sites More sharing options...
oldschool2 Posted August 5, 2009 Author Share Posted August 5, 2009 Thanks for the input: Your input provides useful information. To sum-up the gathered information in addition to your above information > The sensor is in the thermostat housing and has a single wire leading out that goes into a wiring bundle. At the fan motor end there are 2 wires (1 from sensor)connecting to the fan motor. I think 1 wire is a ground. = 2 wires total. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 5, 2009 Share Posted August 5, 2009 Turn to the FSM (from the link) to the "Fuel System" in section EF I don't know what year you have but the 1980 ZX Aux Fan is page 45 of section EF. It's a little more elaborate that a simple ground to a water temp switch, there is a timer controller under the right side (under the glove box area) and a tie into the ignition circuit. See page EF-46 for pictures of the location of all the parts used to make the fan come on (and just as importantly, turn it off after a time). Quote Link to comment Share on other sites More sharing options...
oldschool2 Posted August 6, 2009 Author Share Posted August 6, 2009 Correct! I mentioned the Timer in my first post. I guess I had Heat Soak of the brain. I removed the top fan ducting piece and it is apparent that the potential for "heat trapping" is indeed present in the Fuel Injector "valley." I suspect that the fan ducting that covers the injector area actually adds to the trapping of hot air when the fan is not running (99.9 percent of the time). Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 6, 2009 Share Posted August 6, 2009 I suspect that the fan ducting that covers the injector area actually adds to the trapping of hot air when the fan is not running (99.9 percent of the time). Any air trapping is probably not an issue when the Aux fan is not running (since the BIG fan up front takes care of that when ignition is On!). The difference happens at "key off" when the air from up front stop and the Aux fan keeps air flowing across the rail/injector area for a while. Air is an insulator; that's how foam cups keep coffee from burning your hand. The same principle is used to keep some air flowing between the radiant heat of the exhaust manifold and the fuel rail. It does not cool, it protects and deflects... Quote Link to comment Share on other sites More sharing options...
hughdogz Posted August 6, 2009 Share Posted August 6, 2009 Isn't the fan a "reactive device" (as opposed to a preventative one)? I thought it only came ON when the key is OFF. Quote Link to comment Share on other sites More sharing options...
JSM Posted August 6, 2009 Share Posted August 6, 2009 Why not just add a simple switch and manually hook the thing up? Considering your changing the function anyways. Go get a simple fan relay and therm. switch from a auto parts store. Quote Link to comment Share on other sites More sharing options...
Guest Rolling Parts Posted August 6, 2009 Share Posted August 6, 2009 Isn't the fan a "reactive device" (as opposed to a preventative one)? I thought it only came ON when the key is OFF. Well, yea, that's why Section EF in the FSM was mentioned wit the ignition interconnect and timer circuit. Key "Off" is the condition where the timer circuit and temp sensor are important. Getting a simple "temp On" with "Key Off" might drain a battery (in a component failure mode). Nissan probably added the timer circuit to avoid that mode (and reduce battery drain in really hot places). Quote Link to comment Share on other sites More sharing options...
oldschool2 Posted August 19, 2009 Author Share Posted August 19, 2009 I have added a new Thermo-Temp Switch and Cold Start Valve. I have also started cycling the fuel pump 3 times (Ignition on/off 2 times and on the third cycle I turn ignition switch all the way) as noted somewhere in regards to hot restarts. All I know is that I can now restart my car when it is Hot enough to trigger the Aux Fan. also, can not realistically think of a better plan for the Aux Fan. I will wrap it in double sided foil and that is the end of this project. Thanks for all the inputs. Oldschool2 Las Vegas Quote Link to comment Share on other sites More sharing options...
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