Porsche Enthusiasts Club Forum

Parked the car up on Monday, went to use it yesterday and the (fairly new) battery was as flat as a very flat thing - not enough to light even the dash warning lights (or of course open the tailgate to get at the battery!!). Thought I must have left interior light on.

Disconected battery and charged overnight - reconnected and immediately the engine cooling fan came on. There appear (from the fuses) to be two cooling fans, Fan 1 and Fan 2 (certain logic there!). Removing fuse for Fan 1 did the trick (inasmuch as the fan stopped).

I am assuming that this is a dodgy thermostat?? Anyone experienced similar?

Chris

Could be thermo switch or relay. Pull connector off of thermo switch & if they stop it is the switch. If they don't pull the relay. The thermoswitch is favourite.

I had the thermostatic fan switch pack up on me in Scotland last year.We had parked the car and walked around for about an hour and returning to the car I realised the fan was still running. Once home I disconnected the battery until I could fit a new switch.I think they cost about £15 and you need a big spanner(30mm I think).Its screwed into the radiator housing near the top on the nearside with two spade terminals on it.Got mine from Porsche a part.

had a similar problem with mine when i got back from tipec at thoresby, pulled one lead from thermoswitch and fan stopped refitted and pulled other lead and fan continued, got new switch for about £10, and if you are quick you can replace with very little coolant loss

Yes you do lose a bit but although it looks like a lot when its gushing out it probably only amounts to a pint or two.I had one fail on me several years ago and it failed in the off mode so I didnt know anything was wrong until I noticed the temp needle going into the red sector.I pulled off the road smartish and let it cool down for half an hour before slowly refilling the expansion tank.Then I took the two wires off the thermo switch and joined them together with a piece of wire.Got me home with the fan on full time!

When you change the switch the trick is to remover the pressure cap, to release any pressure then refit it.
This will reduce the amount of water that you lose

Common failiure is the thermo switch, the fans have two heat settings which i cannot remember of the top of my head, second one kicks in at the pre set temperature assuming the second one has not cooled the car enough.
I also had the fuse fail on my car,changed it and has been fine since.

I have had the radiator fan thermostat fail on both my 924S and 944S2 one failed closed so the fan ran continuosly and the other failed open hence the fan never came on even when very hot. The 944S2 has the thermostat switch at the top of the radiator where the 924S (2.5l) has it at the bottom so you do lose more water when changing it. Easiest to remove with a deep 30mm socket got mine from Halfords for around £7 and the job only takes around 10 mins on the S2 where the older bottom mounted switch requires you to remove the air filter support bracket to get to it.

You need to be very careful to ensure you get the old gasket out of the radiator and also do not over tighten the switch as the radiator on the S2 is aluminium framed and the 924S some weird plastic looking stuff which look as though they will strip easily.

You can test if it is the switch by removing the cables from the switch and the fan should stop if you short the wires the fan will start again, the 924S has a 2 wire connector the S2 has 3 I believe. My switches were around £15/17 and you need to be careful to get the right temp range.

If you want to borrow my socket you are welcome to collect it sometime.