As suggested check for add on electrical items for poor connections, then go to your grounds, it sounds like you are getting back feed over the circuits as they try and find a good ground. There are a pair of ground points, one on each side of the body below the dash. You'll see a bunch of black wires all connected at one spot.
97 Sahara, 74 Renegade, 72 CJ5, 55 Willy's (the Beast) Boss 302, 6:34 gearing, Bose 901 speakers.
God I miss that Jeep. Forgot the kinda Jeep, 80 SX4.