electric fan drains battery - Page 3

**Tifosi** · #31 (**permalink**) 06-14-2008, 09:19 PM

You could do that, yes, but the condensor fan actually moves quite a bit of air on it's own.

Remember, it's also just a suppliment to the existing fan, so if you're not actually overheating, there's no real need to swap it out, so it may be better to take what you have and connect to the ignition. Trick is, which circut so that it doesn't just kick the fan on and leave it on the whole time the ignition is on.

Of course as you surmised earlier, a different sensor all together (preferably adjustable) could bring it too, but you'd still have that running after shut down thing occasionally.

So, yeah, hook to the ignition, or put in a toggle to get it to stop running when the car isn't.

Oh, hey, here's a thought:

Get a pressure switch that disconnects when the button is 'up' and fit it in with the parking brake switch.

Brake lever down, fan operates off the factory sensor, brake lever up (you set it every time, right?) temp sensor is disconnected and fan can't run til the brake it released again.

Might even be able to tie it into the seatbelt circutry if yours has it.

Be creative, it's cheaper

sc00terpaul · #32 (**permalink**) 06-14-2008, 09:36 PM

those are some really cool ideas. Not sure if I have the know-how to do that. This is what I think I want to do. I want the car to do this:

Temp sensor works normally when ignition is on and car is running. Turning off the key kills the fan and temp sensor doesn't operate.

How would I do that? I know I need to find a wire that goes "live" when the key is turned and probably substitute that wire for whichever wire is being used to power the fan currently. That way it only receives power when the key is on. BUT, where do i get that wire and which one do I replace?

**Tifosi** · #33 (**permalink**) 06-14-2008, 10:02 PM

The sensor operates the ground circut for the relay that operates the fan, so first you'll have to determine which of the two relays mentioned earlier isn't associated with the AC.

Wth a cold engine, turn on the key and turn on the AC. Unplug one of the relays and if the fan quits, that's the one, if it doesn't, then it's the other.

You'll need to disconnect the power supply wire from the relay plug and replace it with a wire from the coil positive terminal. (the coil only gets power when the key is on)

Net result is the sensor will function as normal, but the fan will only come on if (1) the ignition is on and (2) the sensor is telling it too.

The AC function for the fan will still work as normal regardless.

Or, determine which relay is the one that operates via the sensor as described above and just disconnect it period.

In that configuration the fan won't come on at all unless the AC is turned on.

ghnl · #34 (**permalink**) 06-15-2008, 05:18 AM

Quote:

Originally Posted by sc00terpaul

I went into a Kinko's to make some copies and came out to a dead spider.

sc00terpaul · #35 (**permalink**) 06-15-2008, 10:03 AM

I got nothing at all. Charging the battery solved the problem. I am sure it will die again though. It has been a few weeks of driving here, stopping there, fan running in the garage, etc. I agree that there is something wrong here. I have a couple choices. I have newer electric fan that I could replace it with, or I have a car I am parting out and I could steal it's fan. The fan on the parts car never worked, or was not used often as the AC was non-functional when i got the car. Would you go with the more modern one or replace it with the Alfa one?

sc00terpaul · #36 (**permalink**) 06-18-2008, 12:13 AM

So, today I was driving around. I think it got up to 120 for the high. The car was not liking the heat. The funny thing is that the fan didn't go on once. When I got home coolant was boiling. The car was overheating. Still no fan? Weird. The fan used to go on too much. Now not at all. I had been unplugging the relay to shut it off. Now nothing. I jumped passed the temp switch. Still nothing. I took an old battery and tested the aux. fan which ran like a champ. I looked over some posts and tried jumping passed the relays and testing some things, and nothing. Do you think that since I got the car from a guy who never ran the a/c that I am now leaking freon through a bad compressor thus lowering the system pressure and making the fan inoperative? I know the pressure has something to do with the whole thing. Forgive me for being a little ignorant on all of this. The compressor is a little noisy too. I kind of just want to suck out the r-12. Change the compressor and dryer and fill with an r-12 substitute. Do you think that a shop could just suck out the r-12 and keep it. That would allow me to take it home and change out the components and then re-fill with an r-12 substitute. Any other ideas as to why the fan would not be turning on now?