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Tom_in_LA · Guest

I noticed this when replacing the radiator fans. The primary (driver side) fan and motor is slightly larger than the secondary, not by much, but a definite difference. My question is this, when does the secondary fan come on (I have factory air, if that'll help) ? I know there is only one thermo fan switch, and looking under the hood I see only the primary fan running at normal engine temp. Also, it makes me wonder, is sizing a cooling fan and motor such a precise science that Porsche couldn't make them the same size ? I'm sure it would be cheaper for the manufacturer (and consumer) if they were. Anyway, I'm just curious

924RACR · Posted: Sat Nov 02, 2002 4:35 am Post subject:

The different size could be caused by a different unit being used for a replacement.

The second fan will come on (or should) when the AC is switched on - it should force both fans on full-time.

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Lizard · Guest

I do believe that you can replace the smaller motor with one of the big ones wont make that much difference, just mount the smaller blade on the new motor

Fast924Turbo · Joined: 02 Nov 2002 Posts: 122

You can also just replace those heavy fans with a lightweight aftermarket fan for like $100. But you'll only find them at that price on sale.