So now that winter is here I decided to wire in a battery tender on my 15 highlifter. Its been hooked up all day today and tonite noticed the tail lights were slowly flashing. The tail lights were quite dim but flashing. Why? The tender showed green letting me know it was charged. The key was in the ignition but off. One day when i turned off the key and removed it, after 10 minutes I could hear a high pitched sound like the ignition was still on….maybe some electrical gremlins being born?