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Should I have to turn my electric fan on often?


olie05

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I did the electric fan swap almost two weeks ago, and I'm a little confused. I have the fan wired to a switch, and I decided I will turn the switch on when I see the temps get past normal temperature like when I had the old fan on. So far, it hasn't risen past that temperature, and I haven't had to turn the fan on. Even in stop and go traffic there is no need to turn it on... anyone have similar results with an electric fan swap?

-Oliver

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Guest tony78_280z

You sure your temp gauge is correct?

 

It is winter time and air is cool. I notice lately that when I leave my fans off it never gets over 195, (which is where it runs when the fan is on too.) But last summer I had (Still have actualy) Alternator problems, and the fans wasn't getting enough juice. It's the only time I saw my car overheat and it got to about 230 before I noticed and got it shut down.

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I've also have done the electric fan upgrade. I have the thermostaticly controlled switch as well, but the fan only comes on if I have to sit in traffic an extended amount of time or when I get back from a drive, turn off the engine, and in a minute or two the fan will come on for a short while. I live in SoCal, so it's not always the coolest (temperature wise) of places. It used to be of concern at first, but the temperature never gets hot and has been working reliably for over 3 years now.

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Guest tony78_280z
I second what Yasin says. Just do it as it is good insurance.

or just strait wire it to the wire after your AC fuse. Then the fan will come on when the car is running and stay on as long as it is running. Who needs a toggle switch for everything =) I will ONE DAY get a thermostatic switch. I've only got a hundred other things that are far more important right now.

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Guest 240zJake
keeping the thing on all the time won't help u........im assuming that if the fans r always on-then the thermastat will always b open too-is this correct?

If ur car doesn't get up to the operating temperature, then it wont perform as well

 

Thermostat that controls fluid flow not connected to fan

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In my opinion the easiest thing to do is find a few inches of pipe that will fit inside your lower rad hose, then cut a inch or two from the center of your rad hose and connect the two ends with the pipe and a couple of clamps. Once you have that figured out you can get a fan sending unit from a Cavalier or something and find a nut that the sender will thread into. At this point you can drill a hole in the pipe and weld on the nut. (or if the pipe wall is thick enough, simply run a thread tap though it) Install the sending unit in the pipe and wire it up to your fan relay. Of course the pipe you use should be made of copper, brass, stainless.. (something that won't rust)

The is no way that I would simply run a straight toggle switch as I'm scared of the idea of forgetting to turn it on, or perhaps on day somebody else will drive it and not know to turn the fan on and then you've got a baked engine.

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I completely disagree with tony78_280z, you DO NOT want your electric fan running all the time. EFI engines need to get up to an optimum operating temp. and having the electric fan running all the time will impact that expecially if the ambient temperatute is very low.

 

Plus why would yoy want that constant draw on your alternator all the time?

 

Just get the thermostat kit and you will be fine.

 

$27 from Summit Racing, see below!

 

flx-33010_w.jpg

 

Yasin

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I wish I would have noticed this post yesterday, I would have sold you mine really cheap. I listed it on ebay for $2 and 3.50 shipping. Maybe you can still get it cheap if you want a controller like Yasin posted.

 

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=46096&item=7951550976

 

Also, when I changed to having my ECU control the fan I could not get the car to idle up to temp for the fan to come on (during this winter). I had to rev the engine for a few minutes to get the temp up to test the fan. In the cold weather it just doesn't warm up past the thermostat temp.

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Guest tony78_280z

I've heard about that optimum engine temperature for EFI before. And I've thought hard about it.

 

First: I got a carb. And a big motor where keeping it hot isn't a problem =)

 

Second: Engine temperature is controlled by the thermostat not by the temperature of water in your radiator. Thermostat reaches a certain temp and opens to allow the cooler water in the radiator to circulate. When it gets cool enough, the thermostat closes again. The thermostat doesn't care what temperature the water from the radiator is. If anything the cooler water in the radiator will simply cause it to close sooner. Unless of course you have a hole drilled in the thermostat for constant circulation. You wouldn't do this if you had a problem keeping the motor warm, would you?

 

Driving your car at 40 mph in -10o weather with no fan at all will keep your radiator cooler than if you have an electric fan constantly running in the summer. But nobody warns you against this.

 

SO please tell me how my logic is wrong.

 

The constant draw on the alternator is a concern, but right now I have bigger fish to fry. I will eventualy get around to putting a thermostatic switch in.

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The more I think about it, the more it makes sense. Its all in the thermostat (water). I have thought about what yasin said about fuel injection being at optimal running temperature. So, what I do since I drive the car everyday, In the morning I watch the temp. gauge, which takes about 5 min. to get up to 1/4- 1/2 temp with no fan at all, then I watch out everytime I stop moving (stop light or traffic) to make sure the car doesn't go past the half way point, which it still hasn't done. I deffinitely owe that all to the thermostat opening wide open. That means that when I used to run my mechanical fan, the t-stat would stay partialy open almost all the time, where as now I have a feeling the t-stat is at full flow alot more often. Any thoughts on that?

-Oliver

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I don't think that letting the fan run all the time is a serious problem. Belt driven fans run all the time (even ones with clutches still turn a little) The reason for using a electric fan is for MAXIMUM efficiency. For one it's not robbing power from the crankshaft, however that is not the reason car manufacturers use thermostatically controlled electric fans. Any piston engine has it's normal operating temperature and if the engine is below that temperature the fuel mileage and emmisions will suffer (ever so slightly) but car makers are always under the gun to make cars more effiecient cars and every tiny little thing helps. If the engine reaches it's desired operating temperature faster (by not having the fan run) it will be more efficient. It may not mean much to the induvidual but when you look at it's effect on a very large scale (millions of cars) It has a huge impact.

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Guest tony78_280z
If the engine reaches it's desired operating temperature faster (by not having the fan run) it will be more efficient. It may not mean much to the induvidual but when you look at it's effect on a very large scale (millions of cars) It has a huge impact.
This makes alot of sense. I think you nailed the reason behind this myth.

 

Others might chime in on this; But I don't think keeping the thermostat slightly open and hardly ever closing will cause it to fail any sooner.

 

you can get a fan sending unit from a Cavalier or something and find a nut that the sender will thread into
GrayZee, can you tell us where to find this fans sending unit from the cavalier. Is this a unit tapped into the head, or in the hose, or where. It's hard to identify stuff sometimes in an unfamiliar motor in the junkyard. But I like your style!
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I have a griffin aluminum radiator in my 5.0L ford powered 260Z. I am using a 1995 mustang fan (3200 CFM) which I have wired using a thermal switch. When I installed the fan switch, I tested it to make sure that it would come on when the engine reached the prescribed temperature (185 degrees). Unfortunately, the temperature reached 200 degrees, and still no fan. So, I wired in a by-pass switch that gives me manual control. My fan cools the motor back to 180 degrees very quickly.

 

Do I have to turn it on very often?

No, when I start the car and let it idle, it takes about 10 minutes to reach 180 degrees. I do not ever turn on the fan unless I am sitting in traffic. I never use it on the highway, nor in traffic that is moving well.

 

On my old Z (L26), I replaced the stock fan with a flex-a-lite unit that I had wired to run all of the time. This worked well until the fan motor burned up after 9 months of continuous use. Also, the flex-a-lite fan was insufficient as a stand alone fan (even for the six cylinder). It needed to run almost continuously to keep engine temps in check.

 

Moral of the story:

 

Buy a good fan (the Ford Taurus and 1995 Mustang fans pull more air than any aftermarket unit).

Find a thermal switch that works so that the fan will last.

A properly sized fan should only run intermittently (even in traffic).

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This makes alot of sense. I think you nailed the reason behind this myth.

 

Others might chime in on this; But I don't think keeping the thermostat slightly open and hardly ever closing will cause it to fail any sooner.

 

GrayZee' date=' can you tell us where to find this fans sending unit from the cavalier. Is this a unit tapped into the head, or in the hose, or where. It's hard to identify stuff sometimes in an unfamiliar motor in the junkyard. But I like your style![/quote']

 

 

I just used a Cavalier one because it was common and the first car I spotted in the bone-yard. On a 4cyl early 90's Cavy I found the sensor located in the lower thermostat housing (below the thermostat) There are two plugs located there, the one you want has a oval GM style plug with two pins. Make sure you grab the plug and a bit of wire too! All you will need is a 19mm wrench and a wire cutter. Another thing I didn't mention is that a little temp switch like that will never handle the current of a electric fan, so using it via a relay is a absolute must!

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