I've been using an electric fan in my Tracker for a few years now, wired to a dash mounted on/off switch. It's worked fine, as long as I remember to turn it on when I'm wheeling or in a lot of stop and go traffic. Trouble is my CRS has been quite active lately, and I keep forgetting to run it in this hot summer stop and go traffic, and then up goes the temp. I've got a flexilite adjustable temp control to install, and a relay, which I've had and never used. I want to connect the temperture control to the fan, through the relay, but still be able to have my manual overide to turn the fan off for water crossings. I'm having a bit of trouble hooking this all up to work, and figuring out a way to test it without putting a torch to the temp probe,  and was wondering if anyone's done this, and can help me out with a wiring for idiots type diagram. Right now it's a pretty simple hookup, dash switch + to fused power lead, to fan +. Fan negitive to ground. Any help , and this electrical idiot would be highly appreciative.  It's a standard Auto Zone relay, with 5 numbered poles on the bottom.   

switch the relay control wire
it will kill the relay from triggering no matter what the rest of the system says

i made ya a drawing, sorry for the crudness

We wired the fan on all the time the key was on and put the switch into the normal system. Leave it on when you drive and when you get to the water then just switch it off. In years we ran this we only burnt out one fan and they were all junkyard fans anyway.

Aw man, you guys are alright! Thanks all, especially locjaw for the drawing, wiring for idiots! that'll work!

  Got it wired up and working great! Thanks for the help Guys!

Aw man, you guys are alright! Thanks all, especially locjaw for the drawing, wiring for idiots! that'll work!

my wiring isnt idiotic, just the drawing

  Your funny my humble friend, but we both know the idiot here is behind the wheel of a turbo tracker, now with an automatic, relay actuated fan with a manual off switch!

Ok, got what I think is just a minor issue: when I went out this morning to leave, I was checking over the wiring and noticed the relay was warm to the touch. All other aspects of the fan worked great, came on automaticlly, and I can shut it off at will. It also seems to blow harder, maybe being wired directly to the battery instead of thru the switch and fuse box gives it more amps? The Dash switch was left in the " on" position all night, and only goes to off when I want the fan off. Just for ha ha's I turned the dash switch off, and in a minute the relay was cool again. Is this normal? It doesn't seem to be, as none of my other relays, of road lights, and ARB compressor are warm. I must have something incorrect, but the thing does work fine.

i boo bood, you need the relay thru ignition also
ill revise the drawing

but thats weird, because the relay shouldnt be warm unless there is power going thru it, reguardless of the contacts. the thermostat is just another switch. if it's not hot, it shouldnt work

if you run it thru the ignitionit will kill the ppower at the begining of the circuit

According to the way we have it wired now, there is power going to the relay , directly from batt +. That's why electrics baffle me, all those little symbols are like reading martian to me.

You just need to think of a relay as an electrically powered switch.  Instead of flipping the switch manually to turn it on you flip a bit, from 0 to 1 (aka , no voltage or voltage).

The advantage of using a relay is you don't have to run your larger wires to the switch and your switch doesn't have to handle the voltage/current that it takes to run your electrical devices.  So it saves your dash from going up in smoke. 

I've also noticed the fan works better, stronger flow. I did find a solution to the switching issue:

Nice. 

I need to put an electric on mine.  Not so much for extra air flow, I just hate how much room the manual fan takes up.  Maybe when I swap motors out...

Yeah, the electric sure leaves a lot of extra room in there to work, especially when doing the timing belt, and water pump stuff. The reminder is all I need to make me flip the switch when I get in. Simple and effective. I could have just gone that route in the begining, but this way I have the thermostat, and the relay. No chance of melting the switch, which actually happened once already. Better safe than stupid.