991.1 A/C fan runs all the time

[KMartin]

I have a 991 (2013). The other day while driving the A/C fan came on full blast and would not turn off. It even runs when the ignition key is removed and the car is locked.

To get it to turn off and not drain the battery I had to pull the A/C fan fuse in the passenger side fuse block.

Can any one clue me in on what might be the problem. I would try a new relay but I don't even know where the relay is located. Or it could be a temperature sensor? Or bad switch? No fiddling with the heater controls stops the fan or even slows it down.

Thanks for any help.

[flgfish]

Did you ever figure this out? It just happened to me today as well. Same symptoms. 2015 c2.

[KMartin]

Originally Posted by flgfish

Did you ever figure this out? It just happened to me today as well. Same symptoms. 2015 c2.

I wound up taking it to a dealership.

It's been too long ago. I don't remember the exact solution. But it was an electronic capacitor or something of that sort that the dealership replaced.

If I remember right, they did while I waited. And I don't remember of it being all that expensive.

Good luck with it.

[Mark44]

Originally Posted by KMartin

But it was an electronic capacitor or something of that sort that the dealership replaced.

If something turned on and wouldn't turn off, my first thought would be a relay with stuck points. I could be way wrong, but I don't think capacitors are involved at all. The things that live in a relay panel are relays (sort of cube-shaped components). The fuse panel contains a bunch of fuses.

I wish someone would come out with a manual equivalent to the Bentley book for 996 models. It says that the relay panel is above the fuse panel in the left footwell, and that relay 18 controls the AC and heater fan. There's no guarantee this relay is in the same place for 991 models.