Need Location of Coolant Temp Sensor for 98 A4 Avant

[Bill Rowe]

Car cranks but won't start.  Found full text of TSB that addresses
problem.  Could be due to a bad coolant temp sensor.  TSB reads.....
"for location, see Repair Manual Repair Group 24".  Unfortunately, I
don't have manual.  Family album shows the following:

- 4 pin (blue) dual temp sender p/n 078 919 501 B
- 4 pin (green) dual temp sender p/n 059 919 501
- 4 pin thermo switch p/n 8DO 959 481 B

I'm guessing that a sender and a sensor are 2 different things so if I
had to guess which one is the temp sensor I'd go w/ the thermo switch.
Any help here would be appreciated.  Thanx.