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		|  08-22-2018, 10:11 AM | #1 |  
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				Join Date: Jun 2012 Location: Peoria IL 
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				Cooling fans hi & lo
			 
 
			Had a bad resistor. Fan would not function at low speed. Hi speed, no problem. 
So after about 3 years, I finally attack this and replace the resistor. I started the car up and just let it idle while I was cleaning up the garage. Once the temp needle hit the middle of the zero, both fans kicked on. Yippee! 
Then I thought about it and how do I know that was low speed? I don't have an A/C button to press anymore. (Another issue, don't ask.) 
I guess I will have to take it out and beat it up some to get the temp high enough to trigger the hi speed. 
My question is, anybody know what temp triggers the hi speed?
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		|  08-22-2018, 01:48 PM | #2 |  
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	Quote: 
	
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					Originally Posted by CoBeerToad  My question is, anybody know what temp triggers the hi speed? |  
I believe that 216F triggers the high speed mode. It can sometimes be hard to get the coolant temp that high. Another fairly easy option is to jumper the fan relays to test both high and low speed operation.
 
I would say that if the high speed is engaged, you'll know it. Sounds like a hurricane under there and often dust and debris will be blown up and around the front of the car if the car is standing still.
		 
				__________________1999 996 C2 - sold - bought back - sold for more
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				 Last edited by thstone; 08-22-2018 at 01:54 PM.
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		|  04-06-2019, 10:47 AM | #3 |  
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				Join Date: Mar 2018 Location: Utah 
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			resurrecting an old thread, ope some of y'all can help me for a moment? 
 I want to be sure I understand the cooling-fan system correctly, before I go chasing its' demons.
 
 IIUC: there are TWO fans, one on each side, which run at TWO Speeds, depending on which relay has triggered them, right?  So if my low-speed fan function is not working, that makes NO difference, once the Hi-Speed is triggered, right?
 
 Using the durametric, I've triggered the low-speed fans, and neither side runs.  I can feel both relays moving, but to be sure, I swapped with known-to-be-good relays; no change.  When I trigger the Hi-Speed fans, both run.
 
 So: if I've correctly understood the other posts about this, that means I've got bad resistors on BOTH fans?  is that common, for both to fail?  Or does this sound like a common-point-of-connection has failed?
 
 Where are the resistors located, physically?  Do I need to pull the bumper-cover to get to them?
 
 It's also my intent to wire-in a switch to run the fans manually, for hot days at the racetrack.  How have y'all done this (those who have): Have you tagged into the wires at the relay?
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		|  04-06-2019, 11:29 AM | #4 |  
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			i just checked schems for you; presume your car is 2000 or later?
 each fan has two relays (total 4 for the front) - high speed each side, low speed each side.
 
 common ground on each side, common power each side, so no reason any kind of failure on one side would impact the other. just unlucky?
 
 i could email schems to you if your email can handle 22 MB (not sure mine can, honestly)?
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		|  04-06-2019, 02:24 PM | #5 |  
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				Join Date: Mar 2018 Location: Utah 
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	Quote: 
	
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					Originally Posted by The Radium King  i could email schems to you if your email can handle 22 MB (not sure mine can, honestly)?
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Oh you're a good man, TRK! ;-)
 
Yes, my car is an '03 S.
 
I'll PM you with an email address. 
 
Sent from my SM-G970U using Tapatalk
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		|  04-07-2019, 09:07 AM | #6 |  
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			The resistors are in front of the radiators clipped to to the air inlet shroud at the bottom. It is fairly common for the resistors to fail and that causes exactly the problem you describe.
		 
				__________________2004 Boxster S Silver - FUNTOY
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		|  04-08-2019, 04:21 AM | #7 |  
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			The low speed resistors are clipped just in front of the front wheels. If you search there are industrial Resistors you can replace them with that are around $10 each. The OEM's are much, much more and either way you have to cut wires
		 
				__________________2002 S - old school third pedal
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		|  04-09-2019, 04:27 AM | #8 |  
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			I used the info on Pedros board. Made a jumper and removed the relays to test HI/LO function. Found my right fan wasnt working at all.
		 
				__________________99 Porsche Boxster
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		|  06-05-2019, 01:19 PM | #9 |  
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	Quote: 
	
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					Originally Posted by kk2002s  The low speed resistors are clipped just in front of the front wheels. If you search there are industrial Resistors you can replace them with that are around $10 each. The OEM's are much, much more and either way you have to cut wires |  
Any idea where these $10 resistors can be found?? output?
		 
				__________________2000 2.7 Boxster 5 spd. Ocean Blue Metallic 28K miles
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		|  06-06-2019, 10:32 PM | #11 |  
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				Join Date: Apr 2013 Location: Pittsburgh 
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			Thanks!So I guess the 100watt 0.5 ohm is the way to go..?
 So many seeming to go bad maybe this should be a sticky..
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		|  06-07-2019, 03:17 AM | #12 |  
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				__________________2002 S - old school third pedal
 Seal Grey
 
				 Last edited by kk2002s; 06-07-2019 at 03:19 AM.
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		|  06-10-2019, 09:27 AM | #13 |  
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				Join Date: Apr 2013 Location: Pittsburgh 
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			Thanks for the links!The first one reads 100watt 0.5 ohm
 The second one reads 75watts 50 ohm
 
 Is this critical and wondering what the oem specs are?
 
 
				__________________2000 2.7 Boxster 5 spd. Ocean Blue Metallic 28K miles
 http://s79.photobucket.com/user/fr3dm/slideshow/Porsche Boxster
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