2008 malibu dash goes out along with the taillights and turn signals

Mastering Voltage Drop Testing with Pete Meier and Jerry Truglia Electric Testing Techniques You Need to Know If you want to fix automotive electrical problems , you need to learn how to first ! Find a wiring diagram and see if the compones you mention have anything in common . Power or share a ground . Do you know about automotive electronic's , control modules etc...
The body control module (BCM) energizes the park lamp relay. Current flow is from the PARK LAMP relay to their respective park and marker lamps and to ground. Ground is provided at G101, G102, G401, and G403.
Turn Signal Lamps
The body control module (BCM) is responsible for controlling the turn signals and hazard lamps. When the turn signal switch is placed in either the left turn or right turn position, the BCM receives a signal from the turn signal switch. The BCM then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, the BCM receives a signal from the hazard switch. The BCM then will send an on-off voltage signal to all the turn signal lamps. All the turn signal lamps will flash including both IPC turn signal indicators. The gauges also are controlled by the BCM
Fuel Gage
The instrument panel cluster (IPC) displays the fuel level as determined by the engine control module (ECM). The IPC receives a serial data message from the body control module (BCM) indicating the fuel level. The fuel gage defaults to empty (E) if:

Speedometer
The instrument panel cluster (IPC) displays the vehicle speed based on serial data message from the body control module (BCM). The BCM receives vehicle speed data from the engine control module (ECM) via the serial data circuit. The speedometer will default to 0 km/h (0 mph) if:

The first thing to do would be to check for DTC'S - diagnostic trouble codes stored in the BCM ,if none check B+ power and the ground circuits for the BCM . Your best bet would be to take your vehicle to a qualified repair shop that knows how to trouble shooting this kind of problem .

Sounds loke a poor connection on the fuselinks . There is a You Tube video on how to test and repair them. https://www.youtube.com/watch?v=-SpsSRGfDQI