Temp sensor help

[Eric]

I need some help getting my dash temperature gauge working again after I 
put a KH into my '85 4kq.  I know it is rather crazy to be running a 
turbo car without a coolant temp gauge, which is why I am trying to fix 
it.  That and I want to turn the boost up and this is kind of a 
prerequisite in my book.

Here is my problem.  I did not pay close enough attention when I took 
the old motor and harness out.  That would not be so much of a problem, 
but the Bentleys don't really cover gauge sensors and their drawings are 
not all that clear on the engine management sensors.

The KH has three sensors on the head water outlet and another one in the 
side of the head.  I will list what I think is correct and please tell 
me where I am off base.  First the small sender on the side of the head 
is the ECU temp sensor.  Then the two prong spade style red sensor in 
the 12 o'clock position on the water outlet is the idle stab temp 
switch.  The twin spade in the 3 o'clock (yellow I think?) is for the 
after run pump.  The 4 pin red unit in the 6 o'clock position is the 
multi-function temp sensor or something like that.

Here is my problem.  I tried to wire the gauge up to the pin on the 
multi-function sensor that seemed like the correct one and nothing.  To 
simplify things I wanted to just move the old gauge sensor from the JT 
engine over to the new motor.  My problem is I don't know which one it is.

The JT water outlet on the head has two temp sensors.  The one in the 12 
o'clock position is pictured below as sensor2, while the one in the 6 
o'clock position is labeled as sensor1.

http://sofadog.net/gallery/Audi

Sensor1 appears to be the NTC sensor the computer used.  The manual says 
the two pins should be indepenant sensors.  I figured maybe the extra 
was to be used by the instrument panel.  If I measure from pin to ground 
I get an open.  If I measure between pins I get a higher resistance, but 
the resistance changes as it should with heat change.  Maybe the sensor 
is bad or maybe I am doing this wrong.  Everything used to work 
perfectly before the swap.

Sensor2 just reads open.  It makes me think it is a temp switch for 
something.

I seem to remember that 4 cylinder VW stuff uses the really simple 
sensors that just thread in the side of the head.  I have some of those 
kicking around also.

Does anyone have suggestions?  It would seem like I could get something 
to work with the existing multifuntion temp sensor, maybe I used the 
wrong pin.

Any help would be greatly appreciated!  I guess this is kind of like the  couple of bolts you have left over when you finish a project, except I have too many sensors and a gauge that doesn't work.

TIA


-- 
Eric Sanborn
'85 4ktq

http://www.sofadog.net/4ktq/