Why does the ac lite come on when i call for defrost,and i don't have heat on 1997 Jaguar XJ6

i changed the heat control valve. i got heat for 20 min. then i got cold air and no heat. When i try to use the defrost, the ac comes on

by in Yonkers, NY on January 28, 2013
2 answers 2 comments
ANSWER by on January 29, 2013
Most cars default to A/C 'on' with defrost , to dehumidify the air,that is normal. Possibly a problem with the temp controls or air mix door(s) in heater A/C case. Is the coolant level OK? Is the engine warming up properly?
ANSWER by on January 29, 2013
2 for 2 ziptie
COMMENT by on February 01, 2013
What was the first '1'???............was I just insulted????????????........:).never mind.
COMMENT by on February 01, 2013
no insult. you answered one b4 that one. GOOD BUDDY LMAO