electric fan drains battery - Page 2

he3r0 · #16 (**permalink**) 07-13-2007, 10:24 AM

just a thought and theoretical blurp...
yours is 85, just as mine,
and I still have fan on crankshaft, is your alfa have been modified?
or all the AC models have electrical fans?
is AC cooler separately? does it have separate fan?

now theoretical part, obviously our alfas have the same engines,
and besides AC, yours is cooled by electrical fan, mine is cooled with "old school" fan... so when I stop my engine, no cooling is present, so analogically, since you have the same engine as mine, no harm should be done if your electrical fan got stopped with the engine? there is still AC thing, but please somebody explain me if there would be any problems if electrical fan got cut off along with the engine?
again im not suggesting any modifications, I just want to get explained something for me...

Tim-Spruill · #17 (**permalink**) 07-13-2007, 10:54 AM

80s model spiders have the regular old mechanical fan on the engine, but the cars with a/c have an extra fan mounted in front of the condenser that helps the system out when extra hot or running the a/c. I am referring to extra fan.

You should check to see if you have one and just do not know it....

Tim

he3r0 · #18 (**permalink**) 07-13-2007, 11:32 AM

Quote:

Originally Posted by Tim-Spruill

80s model spiders have the regular old mechanical fan on the engine, but the cars with a/c have an extra fan mounted in front of the condenser that helps the system out when extra hot or running the a/c. I am referring to extra fan.

You should check to see if you have one and just do not know it....

Tim

AutoSport · #19 (**permalink**) 07-14-2007, 07:14 AM

Firstly the state of the charging system may be a problem-with the ac on, it can show a discharge at idle. The alternator should put out max charge above 1800 rpm, and that is where your tests should be taken. Secondly the aux fan is very important, for without it the ac system will overheat, mostly needed in city driving. Without this fan the ac high side pressures will go way above the 400 psi range and will blow something (a seal, hose, the weakest link). The air temp sensor is a very unreliable piece-it is very inexpensively made and its temp range varies widely from car to car. On later spiders (circa 1986?) they rewired the aux fan relay to the ignition. Not the fuse on the left inner fender but the relay, for the fan, which should be terminal 85 or 86 on the relay. In the early 80's we were instructed to move the sensor from the fan shroud to the space between the radiator and condenser, just letting the sensor "dangle" on its wires between the two on the cars that the battery ran on too long. For it took a handful of sensors to try to get one that operated within the correct temp range. Remember, the aux fan purpose is to cool the cond. not the cooling system. Because of the size of the cond. it needs alot more airflow than the fixed engine fan can supply. It was a nice idea to let the fan run on to cool the system after the car was turned off it is not necessary- so the best way to solve your problem for the long term would be to wire the fan relay to ignition. It would also be wise to clean out the condenser as much as possible with compressed air. Good luck Eric

Tim-Spruill · #20 (**permalink**) 07-15-2007, 03:11 PM

When I conducted the test I had my wife hold the throttle at between 1500 and 2000 rpm. I ignored readings at idle, as I already knew these things do not charge much at low rpm.

Either way, I ordered a new fan from advance auto parts this morning. The one I picked out was the same size, blows lots of air, and only draws 7 amps. I figured just about any new fan is probably better than the original one that Alfa put in. I could be wrong...

http://link.toolbot.com/partsamerica.com/83997

It will not be here for a week or so for some reason. In the mean time if someone has a better idea, I can always cancel the order before they ship.

I actually like the idea of the fan running after the car is shut off. It is just so hot here! The milano is wired up to do that and I have no problems. It is nice to get back into a car and not see the temp gauge skyrocket when you restart.

Tim

Tim-Spruill · #21 (**permalink**) 07-26-2007, 11:45 AM

I replaced the fan with the one I mentioned above. It was a real pain getting the stupid thing to fit on the bracket properly and stuff. Either way, it works!! The air blows super cold, the car starts every time, and the alternator can still keep up!! If anyone else ever has a similar problem, this is the way to go!!

Although, the original fan is a bosch, so ought to be available somewhere....

Tim

Duke58 · #22 (**permalink**) 07-27-2007, 01:42 PM

that cleared up things a bit
i have graduate so I dont have AC,
and in my volvo I have only one fan that cools both
radiators at once, thus my confusion

I have an 86 Graduate WITH AC. Hmmmm.

Duke58 · #23 (**permalink**) 07-28-2007, 01:39 PM

Does anybody have a picture of the temp sensor?

**Tifosi** · #24 (**permalink**) 07-28-2007, 05:23 PM

Of the factory sensor?

While not a photograph, info in this thread may be of use.

Duke58 · #25 (**permalink**) 07-29-2007, 09:39 AM

Yes, Tifosi. Thanks very much!

Duke

**Tifosi** · #26 (**permalink**) 07-29-2007, 12:35 PM

It just dawned on me that I've got the sensor I pulled off mine a couple weeks back sitting out in the garage.

So, a quick trip outside with the camera, and here ya go, an actual photo of the elusive auxillary fan temperature sensor.

Duke58 · #27 (**permalink**) 07-29-2007, 01:11 PM

Very nice. Thanks for taking the picture and posting it.

I'm still looking for the one on my car. I know its there somewhere...

Duke

sc00terpaul · #28 (**permalink**) 06-14-2008, 08:45 PM

I went into a Kinko's to make some copies and came out to a dead spider. I have only had my 1984 for a few weeks now. I am having this exact problem. I live in Phoenix, and in the day it has been hitting in the mid 100's to 110's. I am sure the engine compartment is even more after sitting in the sun (the car is dark grey) So, the fan just kinda has a mind of it's own out here. I tried relocating the sensor to no avail. I have a fan from IAP that has a thermostat. I was going to fit it to replace the radiator fan. Should I replace the condenser fan instead? Or, can I just rewire the condenser fan? How would I go about doing either task?

**Tifosi** · #29 (**permalink**) 06-14-2008, 08:59 PM

Actually, you could take a completely seperate route and put a toggle switch in one of the wires to the stock sensor, or at the relays that control the fan proper. (the pair on the passenger side on the fenderwell near the plenum)

Leave it 'on' when the car is running so it can cycle like it normally would in traffic or in conjunction with the AC, then turn it 'off' when you plan on leaving it out in the parking lot or wherever, but don't want the fan howling away for some stupidly long period of time.

That way you don't have to fiddle with any relocating or swapping.

My 2 cents on the removal of the stock belt driven fan to replace with an electric one is 'don't'.

It'll draw just as bad as the condensor fan, prolly even act the same way AFA running after you walk away, and in all probability not cool as effectively as the stock fan does (provided you have the wider bladed US spec fan in there that is)

sc00terpaul · #30 (**permalink**) 06-14-2008, 10:07 PM

Wouldn't it be better to replace the condenser fan with a newer one that draws less and hook it up to the ignition so it doesn't run off the stupid temp. sensor? I am kinda forgetful and I would hate to forget to turn on the fan and blow up the AC!