Where is my light relay located on my 2002 Jetta tdi

SOURCE: Temperature Sensor in 2002 Jetta TDI

NO the temp sensor is located on the head near the heater hoses close to the 4th cylinder if i am not wrong it is color coded and green

SOURCE: How much oil does 2002 tdi hold?

Synthetic Oil (approximately 4.0 quarts to 4.5 quarts depending)

http://pics.tdiclub.com/data/500/2929traditionaloilchange.pdf

The oil specified for use in the Volkswagen TDi for current models meets the "API Service CG-4" rating. This mark means that the oil has been tested for use in Diesel (C = compression ignition) engines to meet the requirements of a test level called "G" in a 4-stroke engine. The oil may also have been tested for use engines fueled by gasoline, methanol, propane, or other fuels ignited by a spark plug (S = spark ignition). The "S" ratings (SG, SH, SJ, etc.) have no bearing on the suitability of the oil to protect a Diesel fueled engine from the special demands imposed by the higher compression ratios and the tendency for all diesel engines to place soot in the oil.

http://tdiclub.com/TDIFAQ/

http://tdiclub.com/TDIFAQ/TDiFAQ-4.html

SOURCE: Will a faulty coolant temp. sensor keep a/c from working? 02 tdi

no it should not it controls your air/fuel mixture and your timing put your heater control on defrost air to high does ac start

SOURCE: 2002 VW TDI Glowplug light blinking

(glow plug light blinking) I have had this problem also and it was after i changed my timing belt it was because the timing was to far advanced i adjusted to timing with the vag com and pump cam and it solved the problem hope this helps

SOURCE: 2006 vw jetta tdi service engine light reset

With the key in the ignition (but not turned), press and hold the Odometer Reset Button on the right hand side of the panel. While still holding that button, turn the key (although not far enough to start the engine) and then press and hold the Minute button on the left side of the instrument pane(if pressing doesnt work try turning the knob clockwise until service light has gone off and skip the pressing)l. Release both buttons at the same time.