Here's a breakdown of the likely causes:
* Poor Ground Connection: This is the most probable cause. Look for corrosion or loose connections at the ground points for the taillights and turn signal circuits. These points are usually located on the vehicle's body near the taillights. Clean and tighten these connections.
* Faulty Wiring: A break or short in the wiring harness connecting the taillights and/or turn signals could be the culprit. Inspect the wiring for damage, especially near the taillight assemblies and where the harness passes through pinch points.
* Bad Multi-Function Switch (Turn Signal Switch): While less likely, a failing multi-function switch (the stalk that controls your turn signals, wipers, etc.) could contribute. If other switch functions are also intermittent, this is more suspect.
* Bulbs: While unlikely to cause *only* this symptom, check your brake lights and turn signal bulbs. If a brake bulb is blown or faulty, the increased load might affect the turn signals, but it's more likely to affect only the brake lights themselves.
* Fuse: While less likely given the specific problem, a blown fuse is still possible. Check your fuse box for any blown fuses related to the taillights or turn signals.
Troubleshooting Steps:
1. Check the fuses: Locate and inspect the relevant fuses in your owner's manual.
2. Inspect the ground connections: Carefully examine the ground wires and connections at the taillights for corrosion or looseness. Clean and tighten any questionable connections.
3. Inspect the wiring: Look for any visible damage or breaks in the wiring harness leading to the taillights.
4. Test the bulbs: Ensure all brake and turn signal bulbs are functioning correctly.
5. Check the Multi-Function Switch: If you suspect this, it might require professional diagnosis or replacement.
If you're not comfortable working with car electrical systems, it's best to take your Silverado to a qualified mechanic for diagnosis and repair. A poorly repaired ground can lead to more serious electrical problems.
