Wiring scymatic for stero - 1994 Mazda Protege

I'd suggest you to get a wiring diagram for your specific make and model of car, as the wire colors and connections can vary depending on the car and the type of audio system it has. The best place to find a wiring diagram for your 2003 Trailblazer would be a factory service manual or a Haynes manual. These manuals are available for purchase online or at an auto parts store.
If you have already cut the harness and if you don't have the wiring diagram or manual then it could be challenging to determine the functions of each wire. In such a scenario you could use a multimeter to measure the resistance of each wire, then identify which wires are which based on the component they go to. If the wiring is cut, you can also try matching the wire colors with the wiring diagram and connecting them accordingly.
In case you do not have the manual, you can also try searching online for wiring diagrams. However, be aware that not all diagrams found online will be accurate, so it's best to use diagrams from a reputable source. Also be aware that working on car wiring can be dangerous and it's important to take the proper precautions to avoid electric shock or damage to the vehicle.

Is it an aftermarket stero. If so was it installed corretly. If they didn't connect the wires correctly the stero may be wired to a hot wire constant which is why it stays on. However it may be a delay but Still should turn off soon as a door opens. If not time to recheck the wiring

I wish people would learn how to use GOOGLE!!!!
VERY FIRST THING ON A GOOGLE SEARCH, IN IMAGES!

john deere lt155 wiring diagram Google Search

Please be patient, the website below seems to be very slow.

John Deere LT155 Wiring Diagram

probably picked up the wrong power wire for the unit and the power is diverted to the ignition circuit.. have the installation checked by professional audio fitters.

the dash lights dont get fed from the stereo , you may have dislodged the wiring connector from the rear of the dash , give them all a push back on , don't worry about the spare wires , they will be for an electric aerial etc

red wires in auto electrics is the nominal power wire. Use a circuit light tester and if it comes on when the ignition switch is on, or in the accessories position then that is the hot (power )wire.

Most likely the red one. black is ground yellow is memory.

Here are the colours of the factory radio harness and what they do.
1995 Toyota Camry Car Radio Installation Schematic
Car Radio Battery Constant 12v+ Wire: Blue/Yellow
Car Radio Accessory Switched 12v+ Wire: Gray
Car Radio Ground Wire: Brown
Car Radio Illumination Wire: Green
Car Stereo Dimmer Wire: N/A
Car Stereo Power Antenna Trigger Wire: Black/Red
Car Stereo Amp Turn-On Trigger Wire: N/A
Car Stereo Amplifier Location: N/A
Car Audio Front Tweeter Size: N/A
Car Audio Front Tweeter Depth: N/A
Car Audio Front Tweeter Location: N/A
Left Front Speaker Positive Wire (+): Pink
Left Front Speaker Negative Wire (-): Purple
Right Front Speaker Positive Wire (+): Light Green
Right Front Speaker Negative Wire (-): Blue
Left Rear Speaker Positive Wire (+): Black
Left Rear Speaker Negative Wire (-): Yellow
Right Rear Speaker Positive Wire (+): Red
Right Rear Speaker Negative Wire (-): White

The best thing to do is use a factory wire adapter. The main wires you need to worry about are power, battery memory, ground and speaker wires. If you have a power antenna you will need to wire in the remote (normally blue or light blue). The only other wire should be an orange wire for the dimmer on the radio face. This one is not necessary for normal operation. Make sure you have the main 11 wires wired in. Ignition, battery, ground and the 8 speaker wires.

http://www.modifiedlife.com/2000-ford-focus-car-radio-wire-color-codes/