no led

Hi all heres my problem, i have a 300tdi and the one button key fob got broken i am in th middle of buying a second hand one to reprogram but the led light in the middle of the dash dosent work and has never worked since i have had it although the alarm has always set ok, so i bought a new led and fitted but it still dosent light up , so does this mean i will not be able to programe the new key fob and why do you think the led wont light up, does it matter? any help would be welcome thanks red.

did you put it in the right way round? as led's are polarity thingy

yes it just plugs in one way, i have also checked all fuses and relays and all are fine.