Shops, Barns, Varmints, and Trucks - Peterbilt 379 Headlights ?

Peterbilt 379 Headlights ?

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Topic: Peterbilt 379 Headlights ?

Posted By: BuckSkin
Subject: Peterbilt 379 Headlights ?
Date Posted: 27 May 2023 at 11:22pm

Every 379 Peterbilt that I have driven or paid any attention to has had dual rectangular headlights; a few around here have retrofitted single and dual round lights.

I just assumed that all 379s came equipped with dual rectangulars.

Then, I saw one with single rectangulars; like on most all vehicles, the single rectangular is a larger bulb than the duals.

The single rectangular must surely be factory original as I can't imagine anyone installing them otherwise.

This single vs dual light business got me to wondering if it was a year model thing; of course, a Google search just confused the issue further as it always does.

Does anyone know ?

I have to assume that the dual rectangulars predate the singles as I have driven some pretty early 379s that had them.

I love a sealed beam light.

Replies:

Posted By: DMiller
Date Posted: 28 May 2023 at 5:46am

What many figured out was Other model design head lamps will work on any model Pete. Construction or Vocational Series generally had the Rectangle single lamp buckets, aftermarket came out with the single Rounds. All the Aftermarkets now are going or gone to LED.

Posted By: Lars(wi)
Date Posted: 28 May 2023 at 7:18am

The job I just left, there were a 2 or 3 375’s that were single headlight, pretty sure they were different model years, the oldest was a 1993.

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I tried to follow the science, but it was not there. I then followed the money, and that’s where I found the science.

Posted By: BuckSkin
Date Posted: 28 May 2023 at 3:23pm

The one I snapped a picture of is most definitely a 379, with the three-piece riveted hood.

The 365/367s I am seeing do have the single rectangular lights like the 379 I have pictured; but, they have an entirely different one-piece fiberglass hood and no external breathers.

375/377s are aerodynamic hoods, much like a T600 KW, with the headlights molded into the fenders.

I guess, for whatever reasons, the single-light 379s I see have had their lights swapped.

I will say this, a single rectangular sealed beam, while not nearly as impressive looking, will outreach any set of duals I have ever been behind; and, a single round will outperform them all.

Any of them will reach out farther after being rewired to receive full alternator voltage; but, they won't last nearly so long.

Of course, if they have got those pathetic molded-in headlights with the foggy plastic lens, provide them with full voltage and they will soon melt holes in the plastic.

As delivered, most will only read 9- or 10-volts at the headlamp; rewire them to receive full alternator voltage and whatever the alternator is putting out is what the headlights will receive, 14-volts +.

After driving one I have rewired and then have to drive one that isn't, it's like driving those old six-volt cars with a generator.

One thing I did notice in my headlight investigation, while Kenworth W900 and Peterbilt 359 have the absolute best wiper setup, with the blades parking straight up in the center, every later model Peterbilt I looked at going back 40-years, save for the 378, has wipers mounted like a pickup truck, forcing one to have to climb over the engine to access the right side wiper.

The 378 is like most earlier models, with the wiper arm "posts" both being outboard and the ends of the blades pointing at each other when the wipers are at rest.

Posted By: DMiller
Date Posted: 29 May 2023 at 7:17am

Most of the Cement Mixer Chassis Petes around here have the large single rectangle lamps on stanchions, was not until first two decades of 21st that they got streamlined hood lamps.