I'm not familiar with your car model, but as far as the station memory, all electronic radios have two power wires. One is the "switched 12 volts" that turns the radio on when the ignition switch is turned on. The second one is for the station presets and clock memory. That has to connect to something that stays live all the time. It sounds like you have that one connected to the wrong circuit. Typical acceptable circuits include the horn and the brake lights. On a lot of cars the cigarette lighter is not live when the ignition switch is off.
There are also some cars that do not have a ground wire in the radio's connector. There is a separate ground strap for that purpose that must be used. A lot of people try to figure out which is the ground wire by measuring them with an ohm meter and mistakenly find the dash light or tail light circuit because with so many bulbs, they read very low resistance to ground. The tail light circuit is tied to original radios to make the display dim at night, and they're tied to the dash light circuit to tell the display how much to dim.
If you mistakenly use one of those lighting circuits for the new radio's ground, you will either blow a fuse, or the radio will stop working or stop working properly when the dash lights at less than full brightness.
Wednesday, April 6th, 2016 AT 12:57 PM