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Peterson Trailer Tail Light Kit - Waterproof - Stop, Turn, Tail - Incandescent - Oval - Red Lens
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Peterson

Peterson Trailer Tail Light Kit - Waterproof - Stop, Turn, Tail - Incandescent - Oval - Red Lens

Part Number: 421KRUS
In Stock
$14.20
Retail:$28.11
You Save: 49%
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6-1/2" x 2-1/4" Oval. Waterproof, incandescent trailer tail light functions as a stop, turn, and tail light. Durable polycarbonate lens is welded to housing. Flush mount with included grommet and industry-standard 3-prong plug. (1) Bulb. Great Prices for the best trailer lights from Peterson. Peterson Trailer Tail Light Kit - Waterproof - Stop, Turn, Tail - Incandescent - Oval - Red Lens part number 421KRUS can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (1232)
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Peterson Trailer Lights - 421KRUS

Highlights

  • One Light, 3 Functions: Works as stop, turn, and tail light for full rear signaling.
  • Reliable In Any Weather: Sealed, waterproof housing keeps water out during submersion.
  • Simple Power Connection: Industry-standard 3-prong plug makes wiring straightforward.
  • Fits Cleanly and Securely: Flush mounts with included grommet for a recessed finish.
  • Durable Build: Polycarbonate lens is welded to housing for long service life.
  • Low Power Draw: Uses 2.1 amps for stop/turn and 0.59 amps for tail at 12 V DC.
Made in USA

Features to know about

Reliable Visibility Day or Night: Stop, Turn, and Tail in One Light

When you need a simple and dependable setup, this 6-1/2" x 2-1/4" Peterson trailer tail light covers all three essentials—stop, turn, and tail. Powered by a dual-filament incandescent bulb, it runs on a standard 12V DC system and draws 2.1 amps for the stop/turn function and 0.59 amps for the tail. That makes it bright enough to be clearly seen without overloading your wiring. The red lens gives a clean, even glow that keeps your signals clear from every angle.

Protected From Water Damage: Sealed, Waterproof Housing

If your trailer ever sees rain or boat-ramp dips, this light is built for it. The polycarbonate lens is welded directly to the housing, creating a sealed unit that keeps water out and protects the bulb and internals. It’s fully waterproof and submersible, so you won’t have to worry about moisture sneaking in and corroding anything. That means fewer light failures and more time on the road or water without replacements.

Clean Install Every Time: Flush-Mount With Included Grommet

A neat, solid mount makes a big difference in how long a light lasts. This one recesses into the trailer body using the included grommet for a flush finish that looks clean and stays put. The standard 3-prong plug connects directly to most trailer setups without cutting or splicing wires. It can be mounted in any 360-degree position, so you get flexibility on placement with a secure fit every time.

Built to Last: Durable Construction That Handles the Elements

With a tough housing and welded lens design, this light stands up to vibration, road grime, and weather exposure that can take out lesser lights. Even though it uses an incandescent bulb, it’s easy to maintain thanks to its rugged build and proven reliability. When it’s time to replace it down the line, you can drop in an identical unit without rewiring or changing your mount—keeping your setup consistent and worry-free.

Specs

Dimensions

  • Overall length: 6-1/2" long
  • Overall height: 2-1/4" tall
  • Overall thickness: 2-3/8" thick

Dimension diagram of Peterson 421KRUS trailer tail light showing length, height, and depth measurements for accurate fitment reference

Electrical

  • Bulb type: dual-filament
  • Power draw at 12V (Stop/turn): 2.1 amps
  • Power draw at 12V (Tail): 0.59 amps

Warranty

  • Limited warranty: 1 year

Recessed grommet mount installation diagram showing how an oval trailer tail light fits into a trailer body for flush mounting

421KR Peterson Trailer Tail Light w/ Grommet and Plug - Waterproof - Stop, Turn, Tail - Incandescent - Oval - Red Lens

Replaces 436800





Customer Satisfaction Score:

Ratings & Reviews

4.8

1232 reviews
5 Stars
(1056)
4 Stars
(117)
3 Stars
(31)
2 Stars
(6)
1 Star
(22)
Review Sort Icon
by:
Worked great and was a perfect replacement for my broke trailer light. Price and shipping were great.
by:
Etrailer is hard to beat as a source for quality-trailer parts and supplies that ate hard to find locally. The Peterson oval trailer light kit is a good example… quality part, reasonable cost. Thanks!
by:
Very helpful, I will buy from them again
by:
2004 Chevrolet Tahoe
Light kit is overall a nice piece and comes with the installation mounting and wiring parts needed.
My only complaint is I had one of the lamps burn out after only a few hours use but that could have been a fluke.
For best service life I'd recommend upgrading to the LED kit.
by:
Prices are reasonable, service is excellent, shipping is expedient.
by:
The item fit as a replacement for the original on my Tracker Tahoe boat trailer. However, you will need the connecting wiring for the replacement light due to the original plug will not plug into because of the connecting configuration.
by:
These exact Peterson lights were installed on a B&W truck bed 21 years ago from factory. Little has changed over time. The gaskets now are a thinner rubber resulting in a sloppy fit in the hole. They should have left well enough alone.
by:
Needed on tail light for a friends trailer. I've ordered lights from etrailer in the past and really like the products and ease of installation.
by:
The lights are what I expected good quality as advertised. The “ Kit” Purchased for a new install, a video or a template for the cut out would have been nice to have. Plus no link to the optional mounting plate.
by:
Haven’t installed the lights yet, but the ordered was delivered very quickly, and on time with Based on the estimated delivery time. Many Thanks
by:
Purchased replacement light for my boat trailer and what I ordered was an exact fit. Great customer service very knowledgeable thanks
Sara E. Will do business with again
by:
Exactly what I was looking for - easy ordering, SUPER FAST shipping, and customer service was excellent. Even followed up with me to ensure I got the right parts.
Will buy from them again.
by:
I have been an etrailer customer for over fifteen years and have never been disappointed in product quality or level of professional customer service. They ALWAYS have what in need in stock, delivered in an expeditious manner.
by:
Quick delivery. My boat trailer tail light and wires came exactly as ordered
by:
Great company to make a purchase from. Products are completely described, communication is great, and delivery is super fast. If you don't purchase trailer parts from etrailer, it's your loss!
by:
Great fit, Prefer the LED lights Glad I bought them
by:
An exact replacement for a taillight on my trailer that was at least 20 years old. Thanks so much!
by:
Great price. "plug and play" with the existing light that had burned out, same plug.
by:
I was moor impressed with the customer services I received from Dena W.
She was very professional and extremely helpful through this hole process. Dena stayed in constant communication with me through everything that happened with this order. She gets 5 Stars
by:
Just the submersible trailer light I needed
by:
Liked the waterproof features of the manufacturer so far.
by:
Great company to do business with, fast shipping
by:
Excellent products, service and shipping
by:
Delivered quickly. Amazing that a direct replacement was available for a 30 year old trailer.
by:
Always get what I need and order from etrailer.
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See what our Experts say about this Peterson Trailer Lights

  • Solution for Bulb Out Error Code Towing Trailer with 2024 Ford Bronco Sport
    Hey Mike, this is a pretty common issue with newer vehicles and LED trailer taillights unfortunately but there are ways to fix it. You can swap the trailer lights to incandescent like you mentioned or you can add load resistors like the part # ARC22VR on the trailer's wiring for the running light circuit and that will simulate the load.
    view full answer...
  • Amp Load of Peterson Trailer Turn Signal Light # 421KRUS
    The Peterson Trailer Turn Signal Light # 421KRUS is an incandescent light that draws a max of 2.1 amps. I have added a link to a video review of this light for you to take a look at as well.
    view full answer...
  • LED Trailer Taillight Replacement for Peterson 421KRUS
    Hey Westley, we carry the Peterson part # 421KRUS which is a pretty standard size trailer taillight so for a kit that will replace that in LED we have the part # TLL12RK.
    view full answer...
  • Replacement Tail Lights for a Kaper 1T-L6R Taillight
    To replace your Kaper 1T-L6R taillights you are going to want to use the Custer Trailer Tail Light - Submersible - Stop, Turn, Tail - Incandescent - Oval - Red Lens item # G65R. These lights are 6-1/2" long x 2-5/16" tall x 2-1/2" thick.
    view full answer...
  • Can The Bulb In A Peterson 421KRUS Tail Light Be Replaced
    The Peterson Trailer Tail Light # 421KRUS is a sealed waterproof unit, but the bulb will technically replaceable. However, removing the cover to gain access to the bulb will damage this seal and the light will no longer be waterproof, so I do advise replacing the entire light if the bulb has gone out. If you do choose to just replace the bulb and break the waterproof seal, I spoke to Peterson and the bulb that fits this light will be the 1157 style bulbs, like the Diamond # DI79VR.
    view full answer...
  • Troubleshooting Malfunctioning Marker Lights on Trailer
    First, check to see if any of the other marker lights are working. If not, check that the running lights are working at the rear of the trailer, as they're all on the same circuit. If none of the running/marker lights are working, unplug the trailer and check the running light pin on the vehicle's trailer connector while the headlights are switched on, using a circuit tester like part # PTW2993. If you get power on the running light pin, the problem is in the trailer wiring. If it's...
    view full answer...
  • What Size Oval Taillights Fit in Buyer's Products 337LB383ALDT Taillight Mounting Box
    The Buyer's Product # 337LB383ALDT taillight mounting box uses a standard 6-1/2 inch oval grommet mounted tallight like those included with the Optronics Fleet Trailer Taillight kit, # 337LB383ALDT. The kit includes the lamps, grommets and wiring pigtails. The lamps have 6 LED's each, and are sealed to prevent water intrusion. They are much brighter than incandescent lamps, draw only a fraction of the power and will last 50 times longer. If you'd rather use incandescent lamps, I'd recommend...
    view full answer...
  • How Does Light Assembly of Peterson Trailer Turn Signal Light # 421KRUS Uninstall
    The light assembly of the part # 421KRUS needs to come out first and then you can remove the rubber grommet. The lip on the grommet prevents it from being able to pull out when the assembly is holding that lip firmly to the cut out of the trailer. You'll want to push the light from behind the assembly out if you can access it or you might need to gently use a flat head screwdriver to pry it out.
    view full answer...
  • Grommet Dimensions of the Peterson Light # 421KRUS
    The Peterson Light part # 421KRUS that you referenced includes a grommet that measures 7-5/8" L x 3-3/8" W x 1-1/8" D. Check out the review video I attached for more info as well.
    view full answer...
  • Troubleshooting New LED Trailer Tail Lights Not Working
    No, you do not need to add a converter to your 2011 Ford Ranger for the new LED lights on your trailer to work. If you are not getting power, I recommend double checking that your trailer connector has power by using a circuit tester like the # PTW2993 while the turn signals, then brake lights, and lastly the running lights of your vehicle are turned on. If the vehicle connector has power but the trailer lights are still not working you will need to double check that the lights were wired...
    view full answer...
  • Is The Peterson 421KRUS Offered In Amber?
    I do have another option that will match what you need, but Peterson does not offer an amber light to match the # 421KRUS, unfortunately. With that said, you will want the Optronics # ST70AB. This incandescent light is the exact same size as the Peterson (6-1/2" x 2-1/4"), but it does not include the gasket or wire. For that you will need the # A70GB and # A47PB.
    view full answer...

Do you have a question about this Trailer Light?


Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video by:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Brian T
Updated by:
Brian T
Employee Ryan G
Installed by:
Ryan G

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