Trouble activating rds(2002 f150)
 

My user manual has only a single paragraph on how to activate RDS. The manual tells me to "Hold the RDS button down until traffic is displayed". However, i have tried holding down the rds button for over 30 seconds, and it says "rds off' for about 10 seconds, and then just goes away. Ive searched forums, read articles, and they all say "set it up, then go through the following tasks." However, i am stuck at turning it on! What should i do?
2002 f150 xlt 5spd man. (w/premium stereo)