Peterbilt 357/378 Lights

Frequently Asked Questions About Peterbilt 357/378 Lights

Will these lights fit my specific year model Peterbilt 357 or 378?

Most aftermarket lights for Peterbilt 357/378 models are designed to fit trucks manufactured between 1987-2007. However, there can be slight variations in mounting holes and wiring harnesses between early models (1987-1995) and later models (1996-2007). Always verify the specific year range listed for each product, and when in doubt, measure your existing light housings or contact us with your OEM for exact fitment confirmation.

Are LED upgrades worth it over standard halogen bulbs, and will they work with my truck's electrical system?

LED lights offer 50,000+ hour lifespans compared to 500-1,000 hours for halogens, plus they draw 80% less power and produce brighter, cleaner light. Most LED upgrades are plug-and-play compatible with 357/378 electrical systems. However, some older trucks (pre-1995) may require load resistors or flasher relay upgrades to prevent hyper-flashing on turn signals. LED headlights typically require no modifications, while marker lights and turn signals may need these simple additions.

What's involved in installing headlights versus marker lights on these models?

Headlight installation typically takes 30-45 minutes per side and requires removing the grille surround and disconnecting the old sealed beam or composite housing. Most aftermarket options use the same mounting points and plug directly into existing connectors. Marker light installation is simpler, usually requiring just removal of the old light, cleaning the mounting surface, and securing the new light with provided hardware. Always disconnect the battery before any electrical work and use dielectric grease on connections to prevent corrosion.

Which light housing materials hold up best against weather and road debris?

Polycarbonate lenses with aluminum or reinforced ABS housings provide the best durability for 357/378 applications. Avoid cheap acrylic lenses that yellow and crack within 1-2 years. Look for lights with IP67 or higher waterproof ratings and UV-resistant coatings. Stainless steel bezels resist corrosion better than chrome-plated options, especially in winter road salt conditions. For maximum longevity, choose DOT/SAE certified lights from established manufacturers rather than generic imports.

Do I need to buy lights in pairs, and what about different cab configurations?

While headlights should always be replaced in pairs for consistent light output and appearance, marker lights can be replaced individually if needed. Be aware that 357/378 extended hood models require different headlight assemblies than standard hood versions due to mounting angle differences. Sleeper versus day cab configurations typically use the same lights, but some roof-mounted clearance lights may vary. Double-check product descriptions for "extended hood" or "standard hood" specifications to ensure proper fit.