MazdaRx7Racer4Life

http://www.aaroncake.net/rx-7/efaninstall.htm


there, they have a picture which shows how to wire up the e-fan, I am installing a fiero fan but am confused, am I supposed to use the thermostat that is on my car? It only has one cable. (I think, where is the thermostat?) Basically, I have the relay, the cables but I don't know what to do with the thermostat part. Can anyone help?

Roy James

I think you are confusing the mechanical thermostat with the electric thermostat-switch. The mechanical thermostat alows the water to flow past it once the block reaches optimal running temperature. This alows the block to warm up to operating temperature faster and keeps the block in this range.

The switch you need is an electric thermostat switch. You can get this from the parts house, just go near where the fans are they'll have them. What this does is you plug it next to your radiator or somewhere similar and when it gets to the set temperature (of your choice, I'd do 175*F-185*F)

Dont use the schmatic on the top, thats just redundant, im not real sure as to why the relays even there in the first place if the switch side and the load side are going to the same place.... hhmm.. strange.

On a side note, I didnt use the thermostat switch at all, I just had the relay cut the switch on when the key was on the "on" position and this worked fine for me. The only problem with this is it will run the fan when not nessesary, like when the mechanical thermostat is closed and the water isnt flowing through the radiator at all. The good side is it will save you about 20 bucks and be more reliable (only saying the more switches there are the less reliable, I don't know how solid those thermostat switches are)
Anyways good luck.
Charles

Roy James

To find the mechanical thermostat on your Rx7, follow the top radiator hose toward the motor until you run into the "filler neck". This is an aluminum tube that turns into a larger dome flange looking peice with two bolts in it. If you remove those two bolts you should find your thermostat in there. Its a circle peice with a spring looking thing on the inside of a two bar "cage". You can pull it out of its little seat (dont be scared to tugg on it, but dont bend it at all). If you have some gasket goop (RTV ect) you might want to take it off to learn more about it. Its not that bad, if you take it off and the gasket gets really messed up, scrape the whole thing off and either get a new gasket or put some blue RTV on the clean surfaces and then tighten the bolts down gradually.

Again this is only if you want to learn, this has nothing to do with hooking an E fan up to your car.

Charles

Scott 89t2

"The fan thermostat controls the fan, turning it on when needed and off when not. These thermostats are available from most electric fan suppliers, as well as Summit Racing. Searching the Summit online catalogue for "thermostat" will quickly turn up several. The best are all electronic, but the electromechanical work as well."


you need to buy one.......

Roy James

You know some people say that and some dont. I personally don't think that the fan on for 5-15 mins while the cars warming up is a bad thing. The fan isnt going to wear out any sooner, its just a few minutes.

Another thing, if you are going to have it controled by the thermostat, then you need to wire the relay up to the AC compressor "on" wire too, that way if the fan is "off" (ie when warming up) and you cut the AC on the fan will cut on.

Scott 89t2

having it on all the time wastes gas and hp. you might as well leave the stock fan on as you have gained nothing.

Aaron Cake

iTrader: (1)

There is no fan thermostat on the RX-7. You need to purchase a thermostat.

I would prefer that people use the "bottom" schematic. That connects the relay coil to a switched 12V souce, which prevents the fan from comming on if the car is off.

NZConvertible

People who know what they're talking about say that. Those that don't, don't. Running an e-fan constantly is stupid, for the reasons Scott mentioned.
I think you need to read the page again. It's not just at warm-up, the fan is not required when the far is moving fast enough to push enough air through the radiator. It's only used at low speed and when stopped.
If your FC has the optional auxiliary e-fan, you don't need to do that. If it doesn't, connecting the e-fan to the compressor will improve the A/C's efficiency, but it's overkill to use the main fan. That's why the auxiliary one is so small.

MazdaRx7Racer4Life

Ok, I bought the thermostat, an adjustable one and I put it on and set it to turn on when the car was less than half-way in temperature. After a while of driving, I came back and the add-coolant buzzer came on, the car was more than half way hot and it was spilling my coolant, I think it does not spin fast enough to cool properly, Its an e-fan off a 4cyl. Fiero. I just hooked up the ground of the fan to the chasis and used the thermostat as an interuptor for the 12v direct battery source. What is wrong with my setup and why did the car almost overheat and spill out my coolant? Thanks.

Roy James

Well you guys run the thermo, ill keep my 20+. I dont think anyone notices a difference from the electrical draw of an electric fan once its going, at least I dont, if I could feel a difference I'd run the thermo again.

Ive never had an Rx7 with an electrical fan, I guess I should have read the complete FSM before posting. I was merely saying you should have an E fan on when the AC is on.

The mechanical fan has a thermo on it as well that lets it slip and grip and I think at higher RPMs also. Even with the Electric fan on all the time I doubt it pulls as much electrical engergy to make as big of HP drop as the mechanical fan on its lowest "setting" for lack of better terms.

Reguardless thats how I run mine, and how it "feels" the quickest (yes I know you can't judge **** by the SOTP Dyno, so don't start that crap up) and ran the best times, as well as held the thermo guage at 180* perfectly winter or summer, bottom line. I guess is hould add that my car had no emissions, PS, AC or any soliniod/vacum rail. Clean block, in which case the motor probably had a real light electrical drop, or mechanical drop on it, so the electric fan was easily coped for.

Not trying to sound harsh, just my personal experiences as well as some others I've seen.

Charles

MazdaRx7Racer4Life

is it okay to use a 4cyl. Fiero fan? Is it also okay to just use no relay, just the fan straight to an ignition source and a ground source?

Roy James

Yeah hooking it up to the ignition source will work, but it will take a good load from whereever you put it. The best bet for that kind of thing would be if you did an add-a-circuit (which I dont really beleive in, but it will work). Just make sure what ever it is that it will take the amperage load you're putting it on. Like dont put it on some 10amp circuit. Id have to check the manual but the Rx7 might have some spare unused circuits you can use from the fuse box. Also its gotta be a KOEO (key on engine off) circuit or you'll be in trouble.

The 4cyl feiro fan is ok i guess, I dont know how good of a connection the thermostat switch really is, it might have alot of resistance which would have the fan a little slower, but i couldnt tell you without looking at it. I guess one way to do it without checking the resistance values would be to hook the fan straigh to the battery source, and see how fast it turns, then compare it to how fast it turns with the thermo-switch on. I dont trust the factory guage to much, on my S4 before I got a good thermo-guage I had it to come on when the car was 1/4 way high.

Over all id say just run a relay, they are at most like 5 or so dollars from the parts house. Also they are cake to wire up, just follow the picture on the box, or the shcmatic on the top cover.

MazdaRx7Racer4Life

What about the 4cy. fan because I just had it on and my engine overheated.

Roy James

*edit*

MazdaRx7Racer4Life

or ALMOST overheated and the coolant began to spray out of the overflow bottle dump tube. Is it possible that it is not spinning at enough cfm?

Roy James

Yeah i would say its not flowing enough for you. Do you have AC? i was going to say for the time being hook up the AC fan and your feiro fan up at the same time, and avoid excessive idleing. (i guess you have one.. they said it was there, now that i think about it, it might be a push fan on the front)

Accually before i get flamed, you better just get a proper fan, probably the more expensive the better :rollseyes:

NZConvertible

The point is you've taken a big step back from the stock fan, so there's was no point in even changing it. You're shortening the e-fan's life (they're not designed to run constantly), you're stressing the electrical system unnecessarily, and you're wasting gas. If it makes no difference, why does every stock electric fan come with thermostatic control? If you want to do it on your car, fine. But don't post BS about it making no difference.
You'd be wrong. The stock fan draws virtually nothing from the engine when not engaged, but the e-fan will draw as much power as a fully engaged stock fan. Moving the same amount of air requires the same amount of work to be done, no matter which fan you use.
Sorry man, but that's all in your head. Unless you know a way for the e-fan to make the car go faster...

NZConvertible

Too small.
Absolutely not! Ignore the elctrical info Roy James posted, it is very wrong. E-fans pull a lot of current (especially right as they turn on), so a fused feed direct from the battery via a relay is mandatory. Do not connect a fan straight to the stock electrical system.

MazdaRx7Racer4Life

so basically any of those two could be reasons why my efan is not cooling enough to keep my temps down?

NZConvertible

The fan's just too small, that's all.

Roy James

Yeah i have no idea what im talking about. Well.. i guess if you dont read my entire post it'll look that way.

Just run a relay, and a thermostat, thats the BEST way. All im saying is you dont HAVE to have a thermostat and that i personally cant tell a rats difference either way other than the "dollar dropage" in my pocket. You sound about like me, on a limited budget, so i was just saying what you could get by with and probably wont be able to tell either way.

NZ dont half quote me again. At least read my whole post and you would know that I said that I wouldn't recomend running it straight to good circuit that could handle the load of the Efan (you made it sound like i said wrap the smallest wire you can around the smallest fuse you can find and it'll be a faster car, come the **** on).

When my fan cuts on my idle doesnt change, therefore i felt the load was easily coped for. I also mentioned what i have missing from my car, which is probably why i have better results. You are right, if i had a thermo, or a pole switch id get more juice, but frankly, I cant tell enough to bother.

"Yeah hooking it up to the ignition source will work, but it will take a good load from whereever you put it. The best bet for that kind of thing would be if you did an add-a-circuit (which I dont really beleive in, but it will work). Just make sure what ever it is that it will take the amperage load you're putting it on."
"Over all id say just run a relay, they are at most like 5 or so dollars from the parts house. Also they are cake to wire up, just follow the picture on the box, or the shcmatic on the top cover." <--yeah thats very wrong btw. wtf ever.
I dont see anythign wrong with that.. if there is a circuit on there that will handle it.. it will work.. I honestly havnt taken the time to look , which,.. if you read anythign i wrote, is why I said check the FSM.

You know, with people like you me taking the time out to help someone is pretty much worthless.

Bottom line, just spend the money, get the relay, thermo, the proper ga wire, solder all connections (make sure its 60/40 rosin core), heat shrink, dont forget the loom, check resistance values of everything ..... ect ect.. We can make it as complicated as we want, or we can be realistic and try to work with what the guys got.

Aaron Cake

iTrader: (1)

There's a right way and a wrong way to do something. Wiring a fan on all the time, or via a switch in the passenger compartment, is the wrong way. It completely negates the advantages of an e-fan (which aren't that great anyway). Running an e-fan all the time will drag MORE on the engine then simply using the stock clutch fan...Why? Well, number one is that the stock fan is freewheeling when it isn't needed. Two, there are more energy conversions required to run an e-fan (mehanical to electric, then back to mechanical) then the stock fan. Alternators are not efficient devices, and neither is your average autmotive motor. So I would be willing to be that it takes more engine effort to turn an e-fan.

Finally, before I get yet another set of PMs complaining about the e-fan argument, this topic is over.