[928uk] S4 Overheating - Temp Sensor Operation

[Paul R Smith]

I have never noticed fans coming on with a cold engine just because the 
A/C is switched on. Does yours do that now?
(I can't check on my GT now as it currently has zero A/C pressure).

Smiffy

On 05/06/2024 11:58, Paul wrote:
> Here's the section that mentions using the aircon to force the fans on:
>
> *TROUBLESHOOTING THE COOLING FANS (‘87 AND UP CARS)*
>
> Turn the ignition switch on, but don’t crank the engine. Turn the A/C 
> on, with the blower on speed 2. Both cooling fans should run at low speed.
>
>
> I had a problem yesterday, thankfully resolved now - I don't have the 
> original plugs on the ends of the fan leads which fooled me into 
> thinking I'd connected the cables when in fact I hadn't
>
>
> I used the email from earlier because it had some useful info at the 
> beginning, I didn't notice that it had been truncated
>
>
> Paul
>
> 87 S4 Manual
>
>
> On Wed, 5 Jun 2024 at 09:54, Paul R Smith via 928uk 
> <928uk at lists.928.org.uk> wrote:
>
>     That's a big document, and I can't see what you refer to.
>     But I'm a bit confused, the email you are replying to is from
>     2007. Do
>     you have a current problem, or are you pre-emptively checking your
>     fan
>     system?
>
>     Smiffy
>
>     On 05/06/2024 08:17, Paul via 928uk wrote:
>     > For anyone who needs an easy to read diagnostic guide, this is
>     invaluable
>     >
>     > https://www.928gt.com/T-WallyHVAC.aspx
>     >
>     > However, the method he advises to force the fans to run does not
>     work on my
>     > car, probably because my aircon has lost pressure and is not
>     operational at
>     > the moment
>     >
>     > Therefore I made this by taking an old temp sensor, breaking off
>     the brass
>     > section, and twisting the wires together
>     >
>     > Then I removed the connector to the radiator temp switch and
>     plugged it in
>     > there, this forces the fans to run with the ignition on
>     >
>     > https://thumbsnap.com/i/JCzAYETX.jpg
>     >
>     > Paul
>     > 87 S4 Manual
>     >
>     > On Mon, 21 May 2007 at 11:45, Paul<ukkid35 at gmail.com> wrote:
>     >
>     >> Quote from EuroCarParts for:
>     >>
>     >> Rad Sensor (Fan Switch)
>     >> Temp Sensor (I or II - not known)
>     >> Thermostat
>     >>
>     >> £90, but at least they are all in stock. I won't know which temp
>     >> sensor they have, Temp I or Temp II, until I see it though.
>     >>
>     >> Not exactly a bargain, but it's no fun when they're faulty.
>     >>
>     >> Paul
>     >> 87 S4 Manual
>     >>
>     >> On 20/05/07, Paul<ukkid35 at gmail.com> wrote:
>     >>> No sign of it escaping from the overflow hose, but I hope
>     that's where
>     >> it's
>     >>> going - where else could it go?
>     >>>
>     >>> Switching the aircon on seems to keep the temp under control,
>     but there
>     >> was
>     >>> an initial very high reading after about 4 mins driving, which
>     then
>     >> dropped
>     >>> to normal, I'm guessing was when the thermostat opened -
>     perhaps there
>     >> was
>     >>> an air lock.
>     >>>
>     >>> I'm tempted to replace Temp I, Temp II, the Rad sensor and the
>     Thermostat
>     >>> all at once. In the past I would have been more frugal, but
>     for once I
>     >> can
>     >>> aford to be a bit more extravagant.
>     >>>
>     >>> Paul
>     >>> 87 S4 Manual
>     >>>
>     >>>
>