Kia Troubleshooting Questions? Ask a Mechanic
My apologies I misread the complete issue you were having. check out the antenna base. replace if needed, they have a lot of issues with the base assembly. You will need to remove the plastic snaps that hold the rear of your headliner up, very carefully pull down just far enough to access the underside of the antenna base. check for a good connection on both antenna leads. also try loosing up the retaining nut that holds base down and retightening, this will insure a good ground. I have had to replace many of the bases for this same issue. check that out and get back with me.