1. Fuses: This is the easiest check. Your Corvette's owner's manual will show you the fuse box location and diagram. Check the fuses specifically related to the headlights (they'll likely be high amperage fuses). Replace any blown fuses with the correct amperage. *Don't just replace a blown fuse with a higher amperage fuse; this is a fire hazard.*
2. Headlight Switch: The headlight switch itself could be faulty. Try wiggling the switch while someone checks if the headlights turn on. A loose connection or internal failure within the switch is possible. Replacement is relatively straightforward but requires some mechanical aptitude.
3. Headlight Relay: C3 Corvettes often use relays for the headlights. The relay acts as a switch for the high current draw of the headlights. Locating and testing the relay is crucial. You can usually swap the relay with a similar one (same amperage and configuration) to see if the problem moves. If swapping relays fixes the problem, you need a new headlight relay.
4. Wiring: Check the wiring harness leading to the headlights and the connections at the headlight housings themselves. Look for broken wires, corrosion, or loose connections. Corrosion is a common problem on older cars, especially in areas exposed to the elements.
5. Headlight Bulbs: Although this seems obvious, make sure the bulbs themselves aren't burnt out. Inspect the filaments visually. Also ensure they are properly seated in their sockets. If you replace the bulbs, ensure they're the correct type for your Corvette.
6. Dimmer Switch (If applicable): If your headlights only work on high beam but not low beam, check your dimmer switch. A faulty dimmer switch can prevent the low beams from functioning.
7. Multi-Function Switch: The multi-function switch (often on the steering column) controls the turn signals, wipers, and sometimes the headlights. A malfunctioning multi-function switch could affect headlight operation.
8. Body Control Module (BCM): While less likely, a problem with the BCM can prevent the headlights from working. This is more difficult to diagnose and may require professional help.
Troubleshooting Steps:
1. Start with the fuses. This is the simplest and quickest check.
2. Visually inspect the bulbs and wiring. Look for any obvious damage.
3. Test the headlight switch and relay. A multimeter can be helpful here.
4. Check connections at the headlight housings.
5. If all else fails, consult a repair manual or seek professional help.
Remember to disconnect the negative battery terminal before working on the electrical system to prevent shocks or short circuits. If you're not comfortable working with car electrical systems, it's best to take your Corvette to a qualified mechanic. A repair manual specific to your 1988 Corvette will be invaluable for finding the fuse box, relay locations, and wiring diagrams.
