My TJ did same thing, changed the ground from battery to vehicle. Fixed it for less then $10 also thought it could have been too large of a load on the battery. Does the voltage drop when brakes are applied?
I have the same seat covers, I've had them about 5 months now. I don't know if this is typical or just me but the tint of my windshield has faded the seat covers to a purple color -- not super noticeable but obviously different compared to the back seat, which is still the original gray and black.