Cooling fan isn't working

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Brian Minson
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Cooling fan isn't working

Post by Brian Minson » Wed Aug 01, 2018 7:25 am

Noticed my 2000 996 C4 Tip running a bit hot in the cool 110 degree heat of Phoenix, Arizona in stop and go traffic the last few days, and with the A/C on the temp would touch the mark between 180 and 250.. NOT COOL!

My drivers side radiator fan wasn't coming on with the A/C, but the passenger side was. Switched the relays around and still the driver side didn't work. Ordered a new fan,tinstalled it last night AND STILL NO FAN with the AC ON!

WTH! Any ideas???

Brian :)

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KoB
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Re: Cooling fan isn't working

Post by KoB » Wed Aug 01, 2018 9:15 am

Brian Minson wrote:
Wed Aug 01, 2018 7:25 am
Noticed my 2000 996 C4 Tip running a bit hot in the cool 110 degree heat of Phoenix, Arizona in stop and go traffic the last few days, and with the A/C on the temp would touch the mark between 180 and 250.. NOT COOL!

My drivers side radiator fan wasn't coming on with the A/C, but the passenger side was. Switched the relays around and still the driver side didn't work. Ordered a new fan,tinstalled it last night AND STILL NO FAN with the AC ON!

WTH! Any ideas???

Brian :)
Burnt out a cooling fan resistor?
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Brian Minson
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Re: Cooling fan isn't working

Post by Brian Minson » Wed Aug 01, 2018 9:19 am

The new fan came with a new resistor... hmmm

Brian :)

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Dr_Strangelove
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Re: Cooling fan isn't working

Post by Dr_Strangelove » Wed Aug 01, 2018 9:25 am

Not to convolute this too awful much, but it's a possibility they sent you a defective fan. Try switching your old good one again and see if it still works.
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DBJoe996
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Re: Cooling fan isn't working

Post by DBJoe996 » Wed Aug 01, 2018 10:14 am

There are four relays for the fans, two low speed and two high speed. Did you switch the low speed ones that will make the fan come on with the AC?
Relay Support 1 Relay Diagram.JPG
Relay Support 1 Plug Position.JPG

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GH996
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Re: Cooling fan isn't working

Post by GH996 » Wed Aug 01, 2018 11:38 am

Hate to mention the obvious but did you check the fuse? When my resistor was bad, it would blow the fuse so the fan would not work on low or high.
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b3freak
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Re: Cooling fan isn't working

Post by b3freak » Wed Aug 01, 2018 1:17 pm

I agree, first check C8 and C9 fuses related to the front fans. (see attached pic) And, check both the Stage 1 and 2 relays.

Question, after driving home, did you check and see if both fans were running on Stage 2 (high speed)? If you're engine was showing temp well above the 180F mark, then the Stage 2 relays should kick in for both fans.

I would also check the old fan by connecting 12VDC bypassing the resistor. Normally, the resistors are the culprits and the fan last a lot longer.
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Re: Cooling fan isn't working

Post by Brian Minson » Wed Aug 01, 2018 3:52 pm

Totally forgot about each fan having its own FUSE! Sure enough, blown fuse... new fuse in and we have FANAGE! lol Skipping beer tonight and right to the Jameson on the rocks! lol

Thanks guys!

Brian :)

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5chn3ll
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Re: Cooling fan isn't working

Post by 5chn3ll » Wed Aug 01, 2018 5:01 pm

If you haven't, consider replacing your fuses with the ones that illuminate once they're blown - makes identifying blown fuses as easy as pulling off the plastic cover.

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