Frequently Asked Questions About Peterbilt 375/377 Cab Lights

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

Most aftermarket cab lights for Peterbilt 375/377 models are designed to fit trucks manufactured from 1987 through 2000. However, there can be slight variations in mounting hole patterns between early and late production years. We recommend checking your existing mounting hole spacing before ordering. The standard 5-light configuration typically uses 6.25-inch center-to-center spacing, but some models may vary. If you're unsure, contact us with your VIN and we can verify compatibility.

Are these cab lights DOT approved and what's the difference between LED and incandescent options?

Yes, all cab lights we carry meet DOT requirements for clearance and identification lighting. LED options draw significantly less power (typically 0.08 amps vs 2.1 amps for incandescent), last up to 50,000 hours compared to 2,000 hours for traditional bulbs, and operate cooler. While LED lights cost more initially, they eliminate frequent bulb replacements and reduce electrical system strain. Both options provide the required amber illumination for legal compliance.

How difficult is the installation if I'm replacing factory lights versus adding new ones?

Replacing existing cab lights is straightforward and typically takes 1-2 hours. You'll need basic hand tools and should disconnect the battery first. For new installations, you'll need to drill mounting holes (use the provided template), run wiring to your clearance light circuit, and seal all penetrations with silicone. The most challenging part is usually fishing wires through the headliner. Many customers report success doing this themselves, but professional installation runs $150-300 if you prefer.

What styles and lens materials are available, and which hold up best?

Common styles include the classic round "beehive" design, rectangular, and teardrop shapes. Lens materials are either polycarbonate or glass. Polycarbonate lenses resist cracking better and won't shatter, making them ideal for harsh conditions, though they may yellow slightly after 5-7 years of UV exposure. Glass lenses maintain clarity longer but can crack from impacts or extreme temperature changes. Chrome-plated bases are standard, with some models offering stainless steel for superior corrosion resistance.

Do I need to buy complete assemblies or can I just replace the lenses?

Both options are available. If your bases and wiring are in good condition, replacement lenses cost about 60% less than complete assemblies. However, check your existing bases for corrosion or pitting first, as damaged bases can cause poor connections and water intrusion. When replacing just lenses, we recommend new gaskets (usually included) and fresh dielectric grease on all connections. Complete assemblies include pre-wired pigtails and new mounting hardware, making them the better choice if your current lights show signs of corrosion or electrical issues.