Frequently Asked Questions About Peterbilt 359 Driving Lights

Will these driving lights fit my specific year Peterbilt 359?

Most aftermarket driving lights for the Peterbilt 359 are designed to fit models from 1967 through 1987. However, slight variations exist between early models (1967-1985) and late models (1986-1987), particularly in bumper mounting points and grille configurations. Always verify the specific year range listed for each product, and contact us with your VIN if you need confirmation for your exact model year.

What's the difference between sealed beam and LED driving lights, and which should I choose?

Sealed beam lights offer the classic authentic look and are typically more affordable upfront, but they draw more power and have shorter lifespans (1-2 years). LED driving lights provide 3-5 times more brightness, last 30,000+ hours, use less amperage, and run cooler, though they cost more initially. For daily drivers or work trucks, LEDs are recommended. For show trucks or occasional use, sealed beams maintain the period-correct appearance.

Do I need to upgrade my wiring or add relays when installing these driving lights?

For sealed beam lights (typically 100-130 watts per pair), your stock wiring may suffice, but adding a relay kit is strongly recommended to prevent switch burnout and ensure optimal performance. LED lights generally require less amperage, but still benefit from a proper relay setup. Most installations require 12-14 gauge wire, a 30-amp relay, and an inline fuse. Complete wiring kits are available and recommended for the cleanest, safest installation.

Can I mount driving lights on both the bumper and grille, or will this overload my electrical system?

Running multiple sets of driving lights is common on Peterbilt 359s. A typical setup with two pairs of sealed beam lights (260 watts total) draws about 22 amps, which most alternators can handle. However, you must wire each pair through separate relays and switches for proper control and safety. LED combinations draw significantly less power - often under 10 amps total for two pairs - making them ideal for multiple light setups without electrical strain.

What size driving lights fit the factory bumper holes, and do I need special brackets?

Factory Peterbilt 359 bumpers typically accommodate 5-inch round lights in the outer positions. Some models have provisions for 4-inch lights in the center positions. Most aftermarket lights come with universal mounting brackets, but factory-style spring-mounted brackets provide the authentic look and better vibration resistance. Measure your existing holes before ordering - outer holes are usually 5.75 inches in diameter to accommodate the mounting ring.