1992 Stealth TT with odd antenna issue

I wanted to find out if this has ever happened to others. I own a 1992 stock Dodge Stealth TT in mint condition with 40K miles. I have an issue with the power antenna that seems very odd. I have to drive the car at least 20 miles or more before the radio antenna will go up or down. Once I have, it works but anything prior to running it 20 miles it won't budge at all. I never heard of a power radio antenna having to warm up? Any body have any ideas before I start tearing it apart? Thanks.