Car Hot - Need Radiator Fan Ballast - Anyone have a spare ?

UGG my drivers fan is not running and today even with the AC on the car was over 100C in traffic - Time to dig in there and swap out the radiator ballast (hope that is what is wrong)... Not sure the cost, but I know a couple people had extra assemblies with the fans and all... I would like to help you clean out your garage if you are so inclined other ideas as to why this is happening? - with the AC on the pass side runs on medium speed and when the temp hit 104 on the readout the fans didnt kick into high speed (that seems odd to me, like they should have.... anyone know when those kick in) I thought maybe thermostat, but with a dead fan, I think its best to start with what I know is wrong. Whay am I whimping out on taking the front end off.... MARC ! (sure it's your fault) LOL

Hah! get to it!

Quotes source post: 7033492

100C or 212F in traffic even on a mild day not uncommon. When I drove my 02 Boxster through AZ in July when ambient temperature as 116F and intake air temperature 135F and coolant temperature 226F engine never complained. (Had fresh (<1000 miles on it) Mobil 1 0w-40 in engine.) When I got back home -- which tells you nothing untoward happened -- talked to service manager who put in call to Porsche. Porsche said as long as coolant light not on or flashing and oil light not on engine is not suffering from any heat issues. Must be right cause I made it out of there and back home at end of nearly 8K mile trip. That was may 100K mile or so ago. With A/C on both fans should at least be on low speed. But even if one not on there should be enough reserve cooling to keep car from overheating. Now this assumes there is no coolant leak and cooling system can maintain pressure. If not... all bets are off. Besides the real problem isn't then the fan is not working but the cooling is not fluid/pressure tight. This is critical to ensure when coolant gets real hot it does not flash into steam. This can lead to localized hot spots in engine and head gasket can fail, or head can crack. Anyhow, in mild weather my Boxster routinely goes to 212F and on hotter days can have the coolant climb even higher. Oh, I don't rely upon the in-dash gage but use a code reader/data viewer and can with this can monitor intake air temperature and coolant temperature in real time. The in-dash gage is really just there for show. Sincerely, Macster.

Thanks Macster, good to have numbers - I feel WAY better! I am using the A/C diaonostics What temp do the fans kick in to high ? Bite me Marc (LOL)

Is it fixed yet??

Its not a SSK Hahaha

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Can't find the info in my (incomplete) 996 manuals but in the Boxster -- and frankly I suspect the numbers are the same or very close for both models -- are the fans come on when A/C switched on, or when the coolant reaches 206F (fans run at low speed) and the fans switch to high speed when coolant reaches 215F or when A/C pressure switch closed (which closes when refrigerant pressure reaches 16 bar). The 996 engine numbers are not going to be too different. A difference of 1 or 2 degrees is not the problem. Not coming on is the problem. Or not switching to high when coolant rises above the high speed fan on threshold. Sincerely, Macster.

is tha Ballast (resistor) responsible for that operation? Can I just swap the ballast out? - any reason NOT to buy a used ballast? (money is tight) I just missed a full set up from a fellow RL member that I knew had one....by 2 days no less OT have you tried DC Auto's website.... man that is a cool set up. LINK They have the entire PET on there I think. (though the breakdown snap shots dont show the part numbers so you have to know or cross reference to PET) Click the picture, takes you in and they show the part and price (many with a picture) - Its really nice (a little high on some of the prices - for used stuff.....IMO)

Quotes source post: 7034482

I do not know what role the ballast resistor plays. I won't be able to find out until sometime Monday. If you have a working radiator fan you can move it to the other side and use it to test the circuitry of the other side to see if the non-working fan is at fault or if the problem lies in the wiring. You can even hook up 12v to the fan and power it from some other source. There is teh slight chance the fan may have gone bad and done something to the wiring. If this is the case you do not want to hook up this fan to the other side and possibly damage the wiring on that side. OTOH, there is the slight chance the wiring on the bad side caused the fan to die. You do not want to hook up the good fan and possibly damage it. Just a thought or two. Sometimes trouble shooting is not as straight forward as it might appear. If you want to move the fans around, or remove the bad one to bench test it, of course you'll have to remove the bumper and disassemble the A/C and radiators to get at the fan. You should not have to break the coolant or A/C line connections if you are careful. But you may need to be sure you support these items properly if you need to unbolt then from the bracket to get to and remove the fans. Be sure you disconnect the battery before you mess with fan to avoid the possibility of the fan coming on while you have your hands around it, even though engine cold if some goofy wiring/electrical problem who knows what can happen?... If wiring at fault then the ballast resistor certainly suspect. These can fail. In a few cases I've been shown the radiator/AC condensor or fan is worked on and the wiring not routed properly and just jammed (or pinched) when the radiator and bumper reinstalled -- Porsche tech who showed me a couple of cars with this problem tells me this quite common when car taken to a body or indy auto shop for repairs -- and this can damage the wiring, the fan or the resistor. Price a ballast resistor and decide if you want to buy one just to test if the old one's at fault. Sincerely, Macster.

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The ballast resistor controls low speed only. When mine failed, the high speed worked fine. The resistor cost me $60 for a new one in June. If your fan is not working at all, check the fuses and relays first. You don't need to remove the front bumper to replace, just the front wheel well plastic liner.

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WOHOOO... I will try that first, I was really dreading removing the front clip (for some reason) THANKS!

^^^ You've done it before, right Ed? Don't be; its pretty straight forward

Quotes source post: 7035121

Thanks for posting the right info regarding the fan. I have only been at the radiators/AC condensors on my Boxster when I was cleaning out the debris and it looked like to get to the fan the front bumper had to come off. Sincerely, Macster.

Quotes source post: 7035418

Macster, I didn't replace the fan only the ballast resistor. Ed, Attached is a pic of the connector location for the ballast resistor.

so I used this link on Renntech and am 100% sure I need a new resistor, the way this guy did it required almost no work to diagnos AND in minutes I isolated the exact part... LINK I hope Loren doesnt kick my a$$ Anyhow, my fan works thanks to the hack/mod and the temps are MUCH better. Now I have time to find a good price on a resistor because I am a tight a$$ LOL... Question? The way this system works when the "low speed" is on the power is diverted to a resistor and then to the fan which I think just reduces the voltage resulting in a lower fan speed. If that is the case, why wouldn't any fan resistor work? A 996 one is $90 new... and 924/944 can be found for $20. I know the mount would be differant, but wouldn't it work..... ??? I am sure I will get an OEM 996 one, but I do have this question for those in the know.....