Why did you spend that kind of money for a factory antenna. I purchased a Metra Power antenna for $50.00 and installed it myself. I have a 99 'tour. I have had the antenna on the car for 3 years now and have had no problems with it at all. I too was going to purchase a factory antenna until I weighed out my options. Can you get a refund on that antenna. If so do it and go and purchase on of the Metra antennas. They work on 12volt.
