At 08:26 PM 1/18/2013, David Clarkson wrote:
>am wondering if I reversed them in the connector. Looking at the
>wiring diagram in the Bentley I see that one is a ground wire and
>the other goes to the gauge. The temperature  overheat/low coolant
>level led does flash normally when the engine is started but I would
>imagine that this might work properly even if the connection was not
>properly wired/connected.

The flasher is an internal gauge function.

>  Is it possible to reverse these and have the gauge not function at all

No, it's not sensitive to polarity, it's just a thermistor.

>  or do I need to recheck my connections with the wires only? I did
> inspect the wires themselves and they do not appear to be brittle
> or have any cracked insulation. Thanks for any wisdom on how this
> wiring works with the sensor.

Unplug the connector and look for +10v on one pin.  If you find it,
ground it for a few seconds max while someone watches the gauge -- if
it shoots up like a rocket then that side is probably all good.  If
it doesn't, you have high-resistance connection somewhere in that
side.  If you don't find +10 at all then you have an open.

For the other side check resistance to ground, should be ~0R.  If
both sides test good, bad connection to sender or open sender.

Yours,
David

>David Clarkson
>90 Westfalia