Since the car was new, I have had to replace either the right or left hadlamp every 4 months or so. Anyone have any diagnoses or suggestions?
First check the voltage. It should never be above 14V. generally around 13.5V when the engine is running.
Next check for mounting causing vibration or corroded/wet connections.
Are you using standard lamps or one of those extra bight lamps, which last a lot less time.
Also, make sure you wipe the bulb with alcohol (the drug store kind, not beer) before installation. Even the slightest fingerprint on the bulb can cause rapid failure.
We had to replace ours at 1.5 years/22k miles.
If your under 3yrs/36k the dealer replaces them for free under warranty.
Is there any condensation in the headlight housing, this can lead to early failures. I pull the left headlight housing off my 2000 Blazer remove the bulbs out and use a hair dryer to dry out the inside.