Temperature sensor Help please (was 5KCSTQ Cold Start Thermo-Time Switch?

[Peter Golledge]

Louis,

The switch only goes closed circuit at the defined temp, which is lot
hotter than hot water (120C? I thought).  Best plan is to heat the heat
shield that the time switch is in with a lighter and verify that the
fan kicks in.


On Tue, 2003-07-22 at 07:05, Louis A. Mulieri wrote:
> Hi Again,
> 	After hearing from Ti Kan that type 44s have a temperature sensor
> rather than a thermo-time switch I located and tested it. I have some
> confusion about whether my temperature sensor is
> defective or not on my 88 5KCSTQ. I pulled off the two harness
> wires from the sensor and could not get anything but open
> circuit readings on my ohm meter (2000K-ohm range). I ordered
> a new one from Parts Bin and checked it out before installation
> only to find it too shows open ckt (even after heating it up in hot
> water). There is also no continuity between either terminal of
> the sensor and the brass shell of both new or old sensors.
> 	Bentley adds further confusion because page 25.99a (for CIS-E
> III system) shows the sendsor I'm testing and claims its
> resistance should be 6000 at -4 F , 1000 at 68 F, and 130 at 176
> F; but then on the previous page it shows the sensor to be a
> Thermoswitch.
>
> Did I get a bad sensor from Parts Bin (the brass and plastic
> portions of the new one looks kind of dirty from shelf age but
> shows no signs of having been installed previously) or perhaps
> does the negative temperature material inside the unit require
> 12 V excitation to show its operating properites (my digital ohm
> meter has only a 9 V battery in it) ?
>
> Thanks for suggestions on what to do next.
>
> Lou Mulieri
>
> >	My 88 5KCSTQ is showing cold start system problems (cranks 5-10
> >sec before a few cyls fire, followed by slow and erratic speeding up to
> >normal idle and normal running). Probst shows the cold start vlave to be
> >controlled by a thermo-time switch having a 2-terminal connector.
> >Audi Archives claim this switch is located in block above cyl 2. All I
> >find is a single wire, slip-terminal sensor in the block at this
> >location.
> >Bentley doesn't seem to indicate where the switch is located. And the
> >section
> >on "Cold start valve power, checking" (page 25.100 for my CIS-E III
> >system)
> >doesn't seem to include possibility of cold start thermo-switch
> >malfunction). Does my car not have a cold start thermo-switch or where do
> I find it?  Thanks for any help with this.
>
> Lou
> 88 5KCSTQ
>
> P.S. Anyone know what size bulb to substitute for the cold start valve
> coil when testing for the few second energization time?