Frequently Asked Questions About Peterbilt 375/377 Driving Lights

Will these driving lights fit my specific year model Peterbilt 375 or 377?

Most aftermarket driving lights for Peterbilt 375/377 models are designed to fit trucks manufactured from 1987 through 2007. However, there can be slight variations in bumper configurations between early models (1987-1999) and later models (2000-2007). Always verify the mounting bracket compatibility with your specific year and bumper style before ordering. If your truck has been modified with an aftermarket bumper, you may need universal mounting brackets instead of model-specific ones.

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

Halogen lights are typically less expensive upfront and produce a warm, yellowish light that cuts through fog well. However, they draw more power (usually 55-100 watts per light) and need replacement every 1-2 years. LED driving lights cost more initially but use 60-80% less power, last 30,000-50,000 hours, and produce a brighter, whiter light. For Peterbilt 375/377 trucks doing long-haul or night driving, LEDs are usually the better investment despite the higher initial cost.

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

Yes, you should always use a relay and appropriate gauge wiring when adding driving lights to your Peterbilt 375/377. For halogen lights, use minimum 14-gauge wire with a 30-amp relay and 20-amp fuse. For LED lights, 16-gauge wire with a 20-amp relay and 15-amp fuse is typically sufficient. Never tap directly into existing headlight wiring as this can overload the circuit. Most quality driving light kits include a wiring harness with relay, but verify this before purchasing.

Can I mount driving lights on my Peterbilt if it has a Texas or low-profile bumper?

Texas bumpers and low-profile bumpers often have limited mounting space compared to standard bumpers. You'll need specially designed low-profile mounting brackets or bumper-specific light bars. Some drivers successfully mount smaller 4-inch round or 6-inch rectangular lights using universal L-brackets attached to the bumper mounting bolts. Measure your available space carefully - you typically need at least 5 inches of clearance below the bumper for standard driving lights.

Are there DOT regulations I need to follow when installing driving lights?

Yes, DOT regulations require that auxiliary driving lights be wired to turn off automatically when you switch to low beams. They must be mounted between 16 and 42 inches from the ground and aimed so they don't blind oncoming traffic. Most states limit you to a maximum of four forward-facing auxiliary lights (including fog lights). The lights should be white or amber - avoid blue or other colors as these are typically illegal for road use. Always check your state's specific regulations as they can vary.