Can some of you electrical guru's take a look at these and tell me in what ways I can inmprove these...the key is cost of course-but at the same time an effective system...The way I was going with these diagrams was for the low speed to come on when the themostat reached something like 190F then when either the A/C switch was pressed or when the Water thermo switch reached 207F the low speed would turn off and the high speed would turn on...I am using a dual speed ford taurus e-fan.
The two diagram that are below do roughly the same thing but the set up in the first picture requires some expensive relays...where as the second picture uses a cheaper set of relays to do the same thing...see if ya'll can understand or read what I have put...If I could have some kind of smart circuit disgned then I could eliminate a lot of relays and make this a lot easier--but I don't know how to do that kind of work...any help would be great! thanks!

 

Why bother with two speeds? Take a look at this:

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

 

I am confused, I don't see the "low" stat.
I would simplify it by using a SPDT toggle to select hi/lo.
You just switch high in summer, low in winter.
That stock booster fan comes on a little late for normal cooling use.
Look at this:

 

"Ghetto" switch works fine, as long as you're smart enough to know when to turn it on...I've been using this setup for over 2 years now with no probs, and from what I've heard here most thermostats are a piece of crap...

The first one's got two relays on one power circuit- unusual, but not unheard of...Relays draw more power than most people give them credit for, are you adding a new circuit, or using an existing one off of the fuse box?

I wouldn't use the water thermo sensor's output for anything but the ECU, it's a weak enough voltage signal as it is...

With your second setup, I see the low and high speeds running simultaneously-is that what you want? Also too many relays in that one. I'ts like you're trying to design a transistor circuit.

What the heck is this "pan relay"?

You're on the right track, though it needs to be simplified, with redundancies removed...

 

"cannot find server." i was about to bookmark it, too.

 

He's up - check your DNS settings..

 

haha, like i know how to do that!
i actually had bookmarked it anyways. i just tried it and it worked. didn't work a few minutes ago. eh, it happens. thanks for the heads up.

 

thanks aaron--I have seen your write up before

the fan cools just fine on low speed--but it does get hot sometimes when I'm getting on it...thats why I need the high to come on...the low pulls a lot less current during idle and lows really all I need most of the times...high is just needed to when really hot and when the A/C is on, that's why I want the two speeds...I've thought about

I was leaning more towards the second one anyway...this is coming straight from the battery(fused of course)

as you can see from the second pic, I've removed the old e-fan and used the high setting in its place.

Actually they aren't...when the high is kicked on there is a relay that grounds the signal from the low speed...

Fan relay...on the second pic the left pic is from the FSM!

 

On my simple diagram above, substitute a relay at the SPDT toggle.
Pull it with the booster fan signal.

 

You said something pretty important in that statement. Know what it was?

 

Ummm.....Ghetto?????

 

i think it was "as long as you're smart enough to know when to turn it on." see, i wouldn't know. i could guess a lot, or just flick it on when sitting in traffic, but i have a stock temp gauge so i've never gotten to watch coolant temps. also, i wouldn't wanna deal with a switch when it could be automatic.

 

On an S4, as soon as it climbs past 1/2 is when I turn it on, or, when it's hot out and I run into a couple of lights right before I get to work...It doesn't run 98% of the time I'm driving, which makes it an e-fan actually worthwhile...If ya got 'em running 100% of the time, you're not accomplishing anything...

 

i have an S5, so mine was a hairy notch under halfway all the time (unless warming up and except for the one time i slightly overheated -- that wasn't cool). i just wouldn't want to always have an eye on my water temp to se if its moved. and what if i looked a couple minutes too late? like i said, i dont know when or how often my fan comes on, so i wouldnt have an idea of how often i'd need to flick it on. also, i like my car to be easy for anyone else to drive without worries. if someone needs it for whatever reason, i dont want to have to explain the fan function.

 

Basically anytime I'm gonna be sitting still for a couple of minutes (stop light), or driving real slow, or riding an 18-wheeler's *** for a while 'cause the dumbass won't get out of the left lane- that's the only time I need mine on...I don't really stare at the gauge all the time (although I do have a habit of looking at all of them every couple of minutes), just when the above situations arise, I know to turn it on...It's "hardwired" in my brain now, just like filling up the premix bottle every two days...

 

I would NEVER advocate running a fan switch. Run them with a thermo-switch.