Just a bit of curiosity. Since I'm not very good at the whole electrical circuits thing Where is a good place to connect the positive wire from the new electric cooling fan to the engine bay to supply it with power? here is my plan.
Positive wire from cooling fan to + terminal on battery... with a 25A inline fuse between battery and fan. Toggle switch (Illuminated) on dash to turn fan on/off since I don't want to use a relay. Ground wire to chassis.

Does that plan hold water or is there a much better way to do this? Please let me know.
1987 Sport Model N/A Rx7 (white with NO interior

 

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

Here's a wiring diagram I found (it was from someone's fileserver, but I got there from a thread found after searching "efan" and going through a bunch of threads).

 

The only place a fan should be connected to is the battery.

Other than connecting to the battry with a fuse, your plan is terrible. If you can't or won't use a relay you should walk away from this project now. Leave the stock fan alone, it's probably working fine.

Don't use a manual switch. One day you will forget it.

If you want to do it properly, get a relay and a thermoswitch and see the diagram posted above or in Aaron's page.

That's my diagram. Ignore the optional A/C wire, it's completely wrong. I don't know what I was thinking... The rest of it's fine. The manual switch and 'fan running' light are optional too.

 

The optional a/c wire would allow current from the ignition switched output to backfeed into the a/c compressor circuit and would either make the a/c run anytime the switch was on, or would maybe blow a fuse. I know what you were trying to do with that, though, but it requires at least 2 relays to work that way.

 

Yeah I know, that's why I deleted that attachment from my list ages ago, so it wouldn't show up in the couple of threads I posted it in. Some people can't search for ****, others are just way too good...

 

Haha, I can handle the heat from being smited for having a bad plan! But like I said, since I'm learning I'll just ask all the questions I can and have a fun time learning
Thanks for the diagram. I will do it that way At least someone saw what I was trying to do with the Switch. But you are right, one day I may forget to turn it off Thanks again guys!

 

where can i get one of these and what exactly do i need to get... part readily available from a turbo rx7??? or local shop / part house??? where to install it? etc. etc. etc...

Thanks!

 

I used one from an 89-91 turbo rx7. It threads into the back of the water pump housing on those models. OTher models would require drilling and tapping to install it, as they do not have the hole/threads for it to go into. They are about $50 from malloy mazda (malloyautomall.com).

There are probably other thermoswitches from various vehicles available as well, which will have different plug shapes and thread size/pitches. They will also have different operating temperatures...the rx7 switch in question turns on at 207 and off at 195. If you could find one with a slightly lower temp range (say 195 and 185?) then it would be a little bit better.

Also some aftermarket fans come with their own temp switch/probe that relies on a radiator probe that goes into the fins, and you can also buy these fan controllers at auto parts stores. I have found these to be inaccurate. One day you set them to come on when you want, and the next day, they come on at a completely different temperature.

 

You can find out how to wire an electric fan here. Also will tell you which wire you can tap into for the ignition control for a relay.

http://howto.globalvicinity.com/gv_w...=148&co=1&vi=1

You will also learn how to install a simple voltage switch that gets wired to the stock water thermo sensor to control the on and off set points plus the variance between the two.

Yup, I have also noticed that, I just set the ON point within the OK temp range, which I have around 190-212. It is never exact.

 

That's probably because they're partially exposed to ambient temp as well as the temp of the radiator fins. As ambient temp changes, the actual temp the switch sees for a given coolant temp will be slightly different. That's why the ones that are directly exposed to coolant are better.