Trying to find a variable switch for my manually controlled radiator fan. Its off a 94 ford taurus and its a monster. I can only run it on high and Im afraid Ill go threw another alternator because of the amps it pulls. Any ideas on what switch I should use? I am currently running 10awg wire from the fan to the cab "were the switch is". I am never going to run an auto fan switch, I just dont trust it. I also want to keep it as a manual setup due to racing I will be doing at our local track in the spring.

 

Your cabin switch should be used to trip a relay in the engine bay...saves running all that high current into the cabin and you can use a lighter duty switch.

Why can you only run the fan on high speed and why don't you trust thermoswitches?
If you're concerned, why not just upgrade the alternator?

There's a lot about your current setup that doesn't make sense.

 

Were can I wire it to in order to run a lower current switch?

 

Are you familiar with how relays work?

 

Yes its basically a mech switch. You need current to activate it.

 

So you put the relay near the fan which minimizes the length of heavy, load carrying wire and use the switch to trip the relay.
Since the current required to trip the relay is minimal, the switch and it's wiring can be very light duty.

There are lots of threads concerning efans.
Here's mine and there are lots of others equally as good.

 

why doesn't anyone use the factory cooling fan switch to activate their fan? I guess it only comes on some models, but FD owners use FC thermal switches all the time. The automatic ones trigger a ground at 195 F.



http://www.mazdatrix.com/86-92Electrical-Engine.htm If you want a clean installation and your car didn't come with a thermal switch, you'd just have to get the right thermostat housing off a turbo or A/T car.

 

That would be perfect for the fan's high speed circuit.
I prefer the low speed to activate @ 190° or so.

 

Thanks for the info. I still will never use an auto switch. I had my last car almost fail because of a faulty auto radi fan switch.

 

It would be more likely for me to forget turning on the switch than having the thermo switch fail over time. That's just me though.

If I had to go electric fan, I'd use the thermo switch with some sort of alarm or light to turn on past a certain temp to go along with the stock or a good aftermarket gauge.

 

Beleive it or not Ive never forgot. I always have my eyes glued on the temp gauge. Once it gets just under quarter way up I flip it on.

 

Variable thermostatic switch and relay combo for an electric fan sells for $15 at autozone here and works great.

 

^ those things suck *****.

I use my Power FC to control my fan. It will turn the fan on at a set temperature and then turn the fan off if it falls one degree below that. So when you set it to 87 C (186 or so) it turns on at 86 and then will turn off if it drops to 85.

 

I would just like a digital temp guage and to keep my fan manual.

 

Just out of curiosity, does anyone know the thread pitch on those oem senders? Is it 3/8" npt?

 

It's probably metric.

 

Probably not NPT, because of the o-ring. NPT would use the taper to seal (along with teflon tape), no?

 

http://www.spal-usa.com/fans/automat...es/fanpwm.html

 

Why do u say they suck the one on my buddies 240z has been working great for about 3 years

 

Two reasons:
-The probe is not in direct contact with the coolant so you're guessing at real temp using the temp of the fins. Also, because the probe is just pushed through the core, contact is variable as the radiator heat cycles and the probe's output varies as a result.

-When I tried one of these units the trigger point as well as the cutoff point was never consistent.
Yes, the fan always came on but hardly ever at the same temp and the fan would stay running far longer than it should have.
It's just not a very accurate way to control an efan, IMO.

Basically, when using one of these probe style switches you're trading one indirect, clunky fan control- the stock thermoclutch- for another indirect, clunky method...hardly seems worth the effort.

 

http://www.summitracing.com/parts/FLX-31165/ A little pricey, but well worth the money.

 

A little pricey?
It's a fan control kit that doesn't even supply a relay, which is an absolute must when installing an efan.

 

The kit I and he use does place the probe in the coolant as per instructions.

Maybe it's a different kit, but mine and his seems to work great. Always comes on at the same time and off about 10* cooler or so. Works fine on the canyon roads and in 105* traffic here in sac.

Then again if the probe is just pushed in the core I can hardly imagine consistent results.

I didn't have the option for a clutch type (no room) or I would have stuck with that.