Wiring, Lights & Towing Mirrors
The Best Trailer Light Kits
Two things decide this: whether the trailer goes in water, and whether it is 80 inches wide or more.
Disclosure: we earn a commission if you buy through the Amazon links on this page, at no extra cost to you. Commission never decides a verdict or a ranking position - read our editorial policy and affiliate disclosure.
How we assessed these: Selected on design type and published characteristics. We do not test photometric output; lamp compliance with federal lighting requirements is the manufacturer's certification, not ours.
Short answer
Buy a submersible LED kit sized for your trailer's width. Under 80 inches takes a standard kit; 80 inches and over needs additional clearance and identification lamps, which is a different kit.
The 80-inch rule
Trailer width changes what lighting is required. Narrower trailers need the basic set - tail, brake, turn, license plate lamp and reflectors. At 80 inches and wider, additional clearance and identification lamps come into play. Federal lighting requirements are set out in FMVSS 108, and kits are sold explicitly for one side of that line or the other. Measure your trailer's overall width before ordering.
Submersible or not
If the trailer ever goes down a boat ramp, buy submersible lamps. A hot incandescent bulb in a non-sealed housing entering cold water draws water in as the air inside contracts, and that is the end of the lamp. Sealed LED units avoid both the thermal shock and the bulb socket entirely.
Even on a trailer that never gets launched, sealed LEDs avoid the corroded bulb socket, which is the most common lighting failure on an older trailer.
LED versus incandescent on an old trailer
- Lower current draw. Kinder to tired wiring and a marginal ground - which is exactly the condition of most trailers that need new lights.
- Instant on. Slightly more warning to following traffic than a filament warming up.
- No bulbs. Nothing to corrode in a socket; the failure mode is the whole sealed unit.
- One caution. Very low current can confuse some vehicles' bulb-out monitoring. If your dash reports a lamp failure after fitting LEDs, that is usually why.
Quick picks
Tap any row to jump to the full write-up. How these are chosen - and what we do and do not claim to know - is published in full on our research methodology page.
| # | Product | Best for | Our read | Price |
|---|---|---|---|---|
| 1 |  Optronics Submersible Trailer Light Kit Best complete kit | Rewiring an older utility trailer | Lamps, wiring and brackets in one box | Check price on Amazon #ad Affiliate link - we publish no price; Amazon shows the current one |
| 2 |  Blazer LED Submersible Trailer Light Kit Best for old wiring | Old trailers with tired wiring | Low current draw, sealed LEDs | Check price on Amazon #ad Affiliate link - we publish no price; Amazon shows the current one |
| 3 |  CURT 7-Way RV Blade Connector Plug (trailer side) Replace the plug too | Replacing a corroded trailer plug | New lamps on an old plug is half a job | Check price on Amazon #ad Affiliate link - we publish no price; Amazon shows the current one |
1. Best complete kit
Optronics Submersible Trailer Light Kit
Optronics · Best for rewiring an older utility trailer
A complete lighting kit - lamps, wiring, brackets and license plate light - for a trailer under 80 inches wide. Submersible rating is the thing to check: a sealed lamp survives a boat ramp, and a non-sealed one fills with water on the first launch.
We have not sourced a full specification table for this model from the manufacturer’s own site at a stable address. Rather than repeat figures we cannot cite, the assessment above is limited to what the design and the maker’s published description genuinely establish.
What works
- Everything needed in one box, so there is no second trip for a missing bracket
- Submersible lamps suit ramps and wet weather
- Sized for the common under-80-inch trailer class
What does not
- Trailers 80 inches and wider need a different lamp configuration by law
- Supplied wire lengths may be short for a long trailer
Skip it if
Wrong kit for a trailer 80 inches or wider - that class needs additional clearance and identification lamps.
#ad Affiliate link - we publish no price; Amazon shows the current one
Raw specifications: Optronics’s own page. We earn nothing on that link.
2. Best for old wiring
Blazer LED Submersible Trailer Light Kit
Blazer International · Best for old trailers with tired wiring
LED lamps draw less current than incandescent, which matters on an old trailer with marginal wiring and a tired ground. They also come on instantly, and the cheap failure mode of a sealed LED unit is the whole lamp rather than a bulb.
We have not sourced a full specification table for this model from the manufacturer’s own site at a stable address. Rather than repeat figures we cannot cite, the assessment above is limited to what the design and the maker’s published description genuinely establish.
What works
- Low current draw is kinder to old wiring and weak grounds
- Sealed units with no bulbs to corrode in their sockets
- Instant-on, which gives following traffic slightly more warning
What does not
- A failed LED lamp is replaced whole, not repaired
- Low current can confuse some vehicles' bulb-out monitoring
Skip it if
Not a cure for a bad ground - if your lights dim when you brake, fix the ground strap first or you will blame the new lamps.
#ad Affiliate link - we publish no price; Amazon shows the current one
3. Replace the plug too
CURT 7-Way RV Blade Connector Plug (trailer side)
CURT · Best for replacing a corroded trailer plug
The trailer-side plug for a standard 7-way RV blade connection. Replacing a corroded plug is a twenty-minute job and fixes a surprising share of intermittent light and brake faults - far more often than the fault is actually in the truck.
Published specifications
What works
- Cheap, standard part that cures a lot of intermittent faults
- Screw terminals, so no special crimping tool is needed
- Fits the standard 7-way RV pattern used across the US
What does not
- Only the trailer half - a corroded vehicle socket needs the other part
- Short one-year warranty compared with CURT's structural parts
Skip it if
Not the part you need if your trailer uses a 4-way flat - check which connector you actually have before ordering anything.
#ad Affiliate link - we publish no price; Amazon shows the current one
Raw specifications: CURT’s own page. We earn nothing on that link.
Key takeaways
- Measure trailer width - 80 inches is the line that changes lamp requirements.
- Submersible is non-negotiable for boat trailers and sensible everywhere else.
- LEDs suit old trailers specifically because of low current draw.
- Fix the ground before fitting anything new.
How we sourced this
Every figure on this page came from one of the following, each fetched while the page was written. Where a manufacturer or regulator does not publish a number, we say so rather than estimate it.
Common questions
- Do I need clearance lights on my trailer?
- It depends on width and length. Federal lighting requirements in FMVSS 108 set out which lamps apply to which vehicles; kits are generally sold as under-80-inch or 80-inch-and-over for exactly this reason.
- Can I mix LED and incandescent lamps?
- Electrically yes. It can produce odd behavior with bulb-out monitoring and gives you two different brightness characters on the same trailer, so it is better to replace a set at a time.
- Why do my new lights still flicker?
- Almost always the ground. The lamps and the frame both have to carry current back, and a rusty ground bolt is a resistance in that path.
More in Wiring, Lights & Towing Mirrors
Nearly every trailer electrical fault is corrosion or a bad ground. Knowing which wire does what turns a roadside mystery into a five-minute check.
Read next
Troubleshooting
Trailer Lights Not Working
An ordered diagnostic for trailer lighting faults, including what specific symptoms tell you about where the problem is.
Reference
Wiring Color Codes
4-way and 7-way color conventions side by side, with the honest caveat about aftermarket wiring and how to verify.
Best wiring harness
Best Wiring Harnesses
Vehicle-specific harnesses, replacement plugs and adapters - what each is for and which part fails first.
How to
Install a Wiring Harness
Installing a vehicle-specific T-connector harness, including the power feed question and the full post-install test.
Found something out of date, or a figure you can source better than we did? Corrections get read first. How we research explains how these pages are put together, and contact is one click away.