Electric fan wiring setup

[jdmfreak]

Ok I have been putting off asking about this because I know from searching what everyone is gonna say..

"just use a stock fan"

But let me give you my back story /excuse

I originally swapped a efan (flexalite dual 12")into my supra shortly after purchasing it because my shroud was broke and I always used them on my wheeling trucks... Better cooling at slow speeds and you can shut them off during water crossings.... And I never had problems and everyone always talked about the slight power gain so I didn't see a downside

I then custom made my intercooler pipes with a opposite side input output intercooler

Found out the stock fan actually is probably a "better " option so I went to put it back on and it hit my intercooler pipe:-\

So I continued to run my efans and have since lost my stock fan and would still like to run the efans but I don't need them on a on/off switch In the cab like I have always ran them....

So I bought this


My question is where to take my switched power from so they shut off when I turn off my key.... I also want to put a thermostat override switch in case the thermostat shits out on me and my temp starts to rise....

 

[jetjock]

I use one of those on my D car as an alarm. Cheap and effective. Anyway, why do you want the fans off with the key?

 

[Dan_Gyoba]

Well, I like the idea that the fans can't come on and take fingers off unexpectedly... They usually put warnings on cars with efans that the fans may come on "Any time ignition is on." Still, I'd wire constant power directly from the battery, and run ignition power to the relay. With a low draw like that, it should be easy enough to find a circuit to take ignition power from. I would probably suggest the black/yellow wire at the alternator, which is connected to the IG1 wire via the 15A "engine" fuse.

The thermostat override switch would basically go in parallel with the thermostat. If it's on, the fans come on regardless of what the thermostat says. If it's off, then the thermostat controls it. easy as 1 2 3.

 

[jdmfreak]

Awesome thanks that's what I needed to know

JJ I just don't want them to stay on after I turn my car off... I run a yellow top optima so it shouldn't drain too much but would rather not worry about it

Is 12gauge wire big enough to run to the override switch? And if so can I get power from anywhere in the cab? I don't want to have to run more wires to and from the cab than I need to.... I hate wire clutter

 

[jetjock]

How much current do the fans draw? How much is that stat good for? Mine was only 16 amps. For override wire another relay across the stat to avoid having to run two large wires into the cabin. That way you'll only have to run one small wire from inside.

The problem with e fans aren't so much the fans themselves as piss-poor installation. Do that part right and they'll be reliable. You need to use quality stuff installed right. Me, I wouldn't even be using that thing for fan control.

 

[jdmfreak]

Ok maybe I will use it for an alarm then what would you suggest for control?

 

[IJ.]

Davies Craig do some not bad controllers

 

[jetjock]

You already have an alarm switch built in: water switch #2. Connect something like a piezo alarm to it behind the glove box where it comes in through the firewall enroute to the AC amplifier.

For fan control I'd use something like Dakota Digital or Spal. If you decide to stick with that thing you bought use a relay powered off switched 12 volts with the fans wired and fused directly at the battery. The switched 12 can be taken nearby, +B in JB2 or the diag block for example. All power wiring should be at least 10 awg, plated, preferably tefzel insulated and connections crimped with AMP PIDG or equivalent using matching tooling. Anything less, crimp *and* solder.

Fwiw I rewired my car so the fans would run when needed. Prevents heat soak and won't hurt your battery. In fact a little cycling is good for it. As for losing fingers, new flight instructors teach students never to touch a prop while experienced ones teach to stay out of the prop arc altogether. There's a lesson there. Not supposed to be working on the car with the battery connected anyway...

Edit: Took a quick look at Ian's recommendation. Also a good choice. Spendy though.

 

[jdmfreak]

Awesome thanks I will have some decisions to make... Hmmmm

As a side note I solder and shrink tube everything anymore... It's easier and cheaper than crimping with a added reliability bonus

 

[jetjock]

Well, it's cheaper. That's the only thing you got right.

 

[IJ.]

Dakota stuff is a bit exe here so up there with DC

 

[jdmfreak]

Huh? So a good soldering job isn't as reliable as crimping? How about resistance? I was under the impression that soldering was the best way to go..... Inform me wise one:
Also for a lot of places I can get a soldering iron in as easy or easier than my crimpers

 

[jetjock]

Dakota stuff is a bit exe here so up there with DC

Only cuz that funny money you use is worthless

jdm: We've been through this before. Crimping, as long as it's done with quality stuff and tooling to match, is superior in every way. Why it's used on aircraft/spacecraft

 

[IJ.]

Only cuz that funny money you use is worthless

Worth more than yours

 

[jetjock]

Sonofabitch, you're right! How did that happen?

 

[IJ.]

Sonofabitch, you're right! How did that happen?

<bows>

 

[jdmfreak]

Which crimps are quality? And how do those crimps resist corrosion? I would like to read a write-up/technical whatnot on this as it doesn't make since right off the top of my head.... I believe you I would just like to expand my knowledge base

 

[IJ.]

There are crimps that have goo and heatshrink and are awesome

 

[jetjock]

AMP PIDG (PreInsulated Diamond Grip) are good. Common in the aerospace biz. It's pretty much all I use. As far as corrosion a properly done crimp is gas tight. The wiring is subject to corrosion from wicking just like in soldering but using plated wire limits that. The environmental splices Ian is talking about are also useful. Google around for the scoop on this stuff. The internet is more than a global pornography network you know...

 

[jdmfreak]

Lol I know just hard to know what info out there is worth trusting.... I really
Like learning and reading just don't wanna waste 2 hours reading and learning false information