electric fan drains battery

Tim-Spruill · #1 (**permalink**) 06-15-2007, 06:34 AM

Alfisti,

It is getting hot here in Louisiana. So hot in fact that the auxilary fan for the a/c condenser is coming on all the time. This is not a problem when the car is running, but it is a problem when the car is parked. When I arrive somewhere the fan will start running a minute or so after the car is parked, unless it is on already. Then it will run for what seems like forever, 15-30 minutes. I am glad that it is helping to cool my car down, but it is draining the battery. The other day I was out somewhere and the fan was still running when I went to start the car again. All I got was the infamous "click". I popped the hood and pulled the fan fuse and the car started just fine. I have also noticed that the first few turns of the starter seem slower than normal every time I go for a ride. This morning, the car would not even turn over until the third attempt. It of course started right up after that, but we took a different car to work anyways (I think the spider hates my wife!).

I am thinking the best approach is to start by cleaning all the connections to the fan so it can run easier. The next step would be to relocate the sensor to either a cooler location or somewhere the fan can blow on it more. Any other ideas or suggestions would be welcome. This car is my daily driver along with the Milano. I have not had a single problem in 6 months with either, I guess it is about time for something major.

Tim

**John M** · #2 (**permalink**) 06-15-2007, 07:16 AM

Hey Tim:

Sounds like either that thing has been rewired or you have a relay stuck open. That fan shouldn't be coming on with the car turned off. I suggest you get a wiring diagram from papajam and trace the system around the fan. And if no signs of modifications....replace the fan relay. I assume it has one without looking at the diagram.....so may be wrong.

Best Regards,
John M

dghii · #3 (**permalink**) 06-15-2007, 08:22 AM

I'm messing with my AC stuff right now and I have to disagree with John. Papajams diagram shows the two relays and their interaction. Relay one, the Aux fan relay turns on with the compressor and runs while the compressor (and ignition) are on. Relay two, the cool down relay, will continue to operate the aux fan until the tem sensor removes power to the relay coil and opens the circuit to the fan.

You either have a bad temperature sensor or the cool down relay is sticking. The cool down relay is the one closest to the front of the car.

Alfacliff · #4 (**permalink**) 06-15-2007, 08:27 AM

might even be a bad battery.
cliff

Tim-Spruill · #5 (**permalink**) 06-15-2007, 08:47 AM

If I remember correctly the Battery and Alternator are less than a year old. The alt is verde spec so puts out a little more juice than the stock spider one. I think the relays are identical. I will try switching them and see if that makes a difference.

I thought about installing a switch in the car so I could manually turn off the fan, but would really like to solve the problem the right way.

It is possible that there is nothing wrong and it is just hot as hell here. Any other daily driver spider owners in hot places? Like the dessert?

Tim

**Slash** · #6 (**permalink**) 06-15-2007, 10:18 AM

Tim, the temp here reaches triple digits regularly from June through September. My cooling fan will come on or stay on after I turn off the ignition and will run for quite a while - even for half an hour - just as yours does. However, this does not seem to run my battery down appreciably.

**PJN** · #7 (**permalink**) 06-15-2007, 10:44 AM

Quote:

Originally Posted by Tim-Spruill

If I remember correctly the Battery and Alternator are less than a year old. The alt is verde spec so puts out a little more juice than the stock spider one. I think the relays are identical. I will try switching them and see if that makes a difference.

I thought about installing a switch in the car so I could manually turn off the fan, but would really like to solve the problem the right way.

It is possible that there is nothing wrong and it is just hot as hell here. Any other daily driver spider owners in hot places? Like the dessert?

Tim

altmand · #8 (**permalink**) 06-15-2007, 11:00 AM

I have experienced the exact same problem, and I don't believe that it is particularly uncommon. Because the thermoswitch that triggers the fan relay is itself triggered by the underhood ambient temperature, hot climates play havoc once the car is parked. The sensor is mounted relatively high on the fan shroud, and that area doesn't cool down quickly if the car is sitting in a parking lot, hot-soaking (the fan's influence, notwithstanding). As others have suggested, make sure the relay isn't getting sticky. Otherwise, a tip-top cooling system will make a difference - if the engine runs a bit cooler, then the underhood temp will be reduced somewhat. A few suggestions:

1. If you have the European narrow-bladed fan on the car, swap it out for the standard fan.

2. Make sure that all cooling-related items are in good shape: radiator, thermostat, water pump, etc.

3. Add a bottle of Redline Watter-Wetter to your cooling system - this product is worth every penny!

If the foregoing does not help, then perhaps you could try relocating the thermoswitch to a location lower in the engine compartment.

Good luck!

-Drew

**Tifosi** · #9 (**permalink**) 06-15-2007, 11:34 AM

It may seem silly, but if you're parked in a secure location, pop the hood latch (no need to actually open the hood) as it'll allow for more of the engine bay heat to escape faster, and the direction of convectional flow will actually sort of pull air from underneath and through the radiator as it flows out up near the cowl with the electric fan assisting by accelerating it. (as in the fan will still run, but for nowhere near as long)

Mmm, Water-Wetter..... Good stuff.

AutoSport · #10 (**permalink**) 06-15-2007, 11:50 AM

Ther is a couple of ways to repair this problem- the most common is to take the thermo switch and put it in between the radiator and condensor. In the design of this system it is obvious the switch is operating at much lower temp than designed- Most all current ac systems use a pressure switch to turn on and off the fans. On systems that sense air temp the sensor is nearer to the condensor.

Tim-Spruill · #11 (**permalink**) 06-17-2007, 05:10 PM

Thanks for all the replys. I still have not cleaned the electronics, but I think it will certainly help with the battery when I do. Either way, I charged up the a/c system with some freeze-12 I had laying around from when I worked at Garcia Alfa Racing. We could not find my a/c thermometer, but it really blows cold! This will help me out, but it will add heat that has to be rejected by the cooling system. I guess I am not helping things out...

The cooling system was completely refreshed when I got the car a couple of years ago. New water pump, rodded out radiator, all new hoses (except to heater core, I am really asking for trouble here.), new thermostat, all belts, and fresh coolant. I replaced the fan with a standard US spec about a year ago when I replaced the motor mounts.

There has been a new development. I have been driving the car all weekend and the electric fan has worked "properly." It only runs a short while or not at all. I think it is possible the relay was sticking from not being worked all winter and is now ready to do its thing after a little early summer workout. We shall see.

I will clean up the connections whenever I get around to it or get stranded. If the heat becomes an issue I will add some water-wetter. Other than that I am not so worried about it now. Besides, having cold air could add a whole new level of problems....

Rev High,
Tim

Tim-Spruill · #12 (**permalink**) 06-17-2007, 05:12 PM

Oh yeah, I forgot... if none of that fixes the problem then I will just move the sensor to a better location and not worry about it.

What are opinions on this fan? Is it really necessary? When was it added to the cars? How were a/c cooling problems dealt with before?

Tim

Tim-Spruill · #13 (**permalink**) 07-13-2007, 06:11 AM

So I went out two nights ago and cleaned all the connections in the cooling fan circuit, all the way to the fan. They were really bad. Now everything is shiny clean, and nice and tight. So I fire up the engine, hook up the volt meter, and start turing things on. The alternator can keep up with everything until I kick on the a/c. First I thought maybe it was the clutch for the compressor drawing too much power. I disconnected the aux fan tried again. Now the voltage is much better. Knowing that the wiring for the fan is fine, I suspect the fan is shot. I brought out the father in law mechanic guru and had him give me an opinion and he agreed with me before I even told him all the symptoms. Just the sound of the fan clued him in! Then I showed him the partly melted fuse and it was clinched, the fan is totally gone.

So now I need a new one. I saw the two aux fans that IAP sells but was wondering if the original is still available and how it compares to the newer options. Does anyone know the cfm of the original? I need to go out with a tape measure and get a diameter also to see which IAP fan could fit. I really do not want to mess with the condenser or radiator to fit up a new fan. Do either of the IAP fans fit up to the same brackets as the original? Some of these questions can be answered by IAP if no one knows.

I sure miss driving my spider....

Tim

Tim-Spruill · #14 (**permalink**) 07-13-2007, 06:14 AM

Sorry if I was not clear enough....

My point is that the battery drain is not coming from an overheating car causing the fan to run too long. It is the fan itself that is causing the drain by being worn out. Now I just want to replace the fan with a new one.

Tim

ghnl · #15 (**permalink**) 07-13-2007, 07:11 AM

Have you tired removing & disassembling the fan's motor to see if a good cleaning & oiling would improve its function?