* Blown Fuse: This is the most common and easiest fix. Check your owner's manual to locate the fuse box and find the fuse(s) for the taillights. Replace any blown fuses with the correct amperage.
* Bad Bulbs: Simply check the bulbs themselves. They may be burned out. Replacement is usually straightforward.
* Wiring Issues: A broken wire, corroded connection, or short circuit in the wiring harness could be the culprit. This requires more investigation and potentially some electrical repair skills.
* Tail Light Switch: This switch, usually located near the brake pedal, may be faulty. If your brake lights work, but the running lights don't, this might be the issue.
* Body Control Module (BCM) issues: While less likely, a malfunctioning BCM can cause problems with various electrical components, including taillights. This usually requires professional diagnosis and repair.
* Grounding Problem: A poor ground connection can prevent the taillights from functioning correctly.
To troubleshoot, start with the easiest and most likely causes – the fuses and bulbs. If those are okay, you'll likely need a multimeter to check for voltage and continuity in the wiring. If you're not comfortable with electrical work, it's best to take your Tahoe to a mechanic.
