Electric fan drained battery

[granttttt]

My flex a lite fan keeps running after I turn off my car. I know that it sometimes should run for a minute after I turn off my car but this thing went on and on until my battery was totally dead.

I recently got my battery recharged(at an autoparts store) because I left an interior light on in my car over night, killing the battery. When I put the recharged battery in my car it fired up, I went home....next morning fired up perfectly. But 2 days later(about 6 starts later) I noticed my fan kept running. Even when the engine temp went far below 172 F(which is when my first Flex a Lite fan turns on.

S13
KA24DE
Dual Flex a Lite fan
Hooked up to a DIF Dual fan controller
Sensor on Defi controller connected to one of the temp sensor on motor

But my temp sensors that are on the motor are fairly new(less than a year old). Fans have been running ok before this situation. It would turn off in like 10 seconds after I turn the motor off.

[240trainee]

Wire them up so the fans Defi unit is drawing ignition power, not constant battery power.

[Lusion]

Have you thought of making a switch for the fan? So when you turn off your car you can control if the fan is on via this switch? When it cools down, you turn it off. Atleast this way you can manually control if your fan is on or off.

Edit. didnt see the Defi fan controller...

[granttttt]

Wire them up so the fans Defi unit is drawing ignition power, not constant battery power.

Thanks, but I personally like it setup onto the battery so that it runs a bit after I turn off the car. Cools down the radiator quicker.

Even if I wire it up to ignition, I also want to find out what is wrong so that it doesn't cause other problems.

[granttttt]

Anybody think I need to change the temp sensor on my motor? Since the DIF controller unit is wired up to it. I did buy my last sensor from a parts store, so it isn't a Nissan product. I guess it could go out in less than a year.

[infinitexsound]

Wire them up so the fans Defi unit is drawing ignition power, not constant battery power.

do what he said... its better... why would u need it to keep on running if ur car isnt... maybe cause it helps cooling to go faster... and engine life...

[bongnak]

the relay is getting stuck even with a switch the current is still going to flow into the fan

supplying the fans thru a source other than the battery will prob burn that source out.
never looked into the dif units but the relays might not be strong enough for the job. open it up and resolder new relays...

my .02 GL

[granttttt]

do what he said... its better... why would u need it to keep on running if ur car isnt... maybe cause it helps cooling to go faster... and engine life...

Alright guys, even if I wire it up to ignition, it will be on all the time when the car is on. The fans should only come on at the temp setting that I controll on the DIF fan controller.

So my question is, what could cause my fan controller to think it is hot when actually my engine is cold?

[g6civcx]

Check all your wiring: http://www.frsport.com/DIF-Dual-Fan-Controller-Install-on-S13-S14-240SX_t_22.html

http://www.frsport.com/writeups/diffc/00-dif-wires.jpg

Make sure the fan1 and fan2 wires are not shorted battery wire. Also check the temp setting and the temp sensor wiring with an ohmmeter.

If everything checks out you may have fried your fan controller. Test with a known good and throw out the old one if necessary.

[IStop4NoMan]

I have had all the same problems with this exact setup.
first, they drew too much power and would drain my battery down to 12V even with the car running. I didnt know it was drawing that much power and the fans would shut off. i tried replacing the DEFI unit, and it didnt help. i upgraded my battery which helped the problem of the fans drawing too much power. but they still randomly turned off and on and sometimes they dont come on at ll. they werent constant at all and i still dont know why they did that. now im back to the clutch fan and stock shroud and my only problem is it runs too cold haha.

[g6civcx]

FYI, Dif has a new version out to replace the old one.

[granttttt]

I have had all the same problems with this exact setup.
first, they drew too much power and would drain my battery down to 12V even with the car running. I didnt know it was drawing that much power and the fans would shut off. i tried replacing the DEFI unit, and it didnt help. i upgraded my battery which helped the problem of the fans drawing too much power. but they still randomly turned off and on and sometimes they dont come on at ll. they werent constant at all and i still dont know why they did that. now im back to the clutch fan and stock shroud and my only problem is it runs too cold haha.

You ever thought about checking the sensor that you hooked the DIF unit to? Seems like changing to the stock fan didn't help much, since it is turning on more often than it should. I would guess that sensor might be sending off bad signals. That is why both the stock fan and DIF controller are going crazy.

[granttttt]

FYI, Dif has a new version out to replace the old one.

Great, that probably means the old version had problems! I wonder if DIF would give me some credit if I turn in the old unit for a new one....

[IStop4NoMan]

You ever thought about checking the sensor that you hooked the DIF unit to? Seems like changing to the stock fan didn't help much, since it is turning on more often than it should. I would guess that sensor might be sending off bad signals. That is why both the stock fan and DIF controller are going crazy.

i did just change out the stock sensor. also i have a temp gauge with a sensor in the upper rad hose. at 180 degrees the FAl fans would kick on, but after driving around for a while, they wouldnt work at all.
the stock fan works good. so much that i dont ever see the temp go over 150 degrees :faint:

[rhs13]

do what he said... its better... why would u need it to keep on running if ur car isnt... maybe cause it helps cooling to go faster... and engine life...

correct me if im wrong, but keeping the electric fans running when the engine is shut off wouldnt help the engine get a whole lot cooler because the coolant isnt circulating thru the block. for the most part, youre basically just cooling what's in the radiator and the heat from the outer surface of the engine.

buying a "turbo timer" would be more effective than letting the fans run after the engine has been shut off, no?

EDIT: point being, i agree with hooking up the system to ACC power, as opposed to a direct battery connection.