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Black rectangular 4-pin trailer wiring tester with male and female flat plugs and coloured LED indicators

UHANBUT 4-Way Flat Trailer Wiring Tester Double End Male Female Plug

SKU CH-1ZQJ-P4J4F

Tests 4-pin flat trailer wiring with LED indicators to locate faulty circuits quickly

  • Team affiliation1 Piece
  • Key features4-Way Flat Trailer Wiring Tester, Corded Electric
  • Overall height2.23 L x 1.32 W x 1.32 H inches
  • Overall width2.23 L x 1.32 W x 1.32 H inches
  • Overall length2.23 L x 1.32 W x 1.32 H inches
  • Product type4-Way Flat Trailer Wiring Tester
  • Diagnose trailer lighting faults accurately with 4-pin flat connector compatibility
  • Plug-and-play operation checks taillights and turn signals instantly
  • Colour-coded LED indicators identify faulty circuits at a glance
  • High-quality ABS housing resists wear, corrosion and impact for long life
  • Compact 2.23 x 1.32 inch size stores easily in any toolbox

4-Way Flat Trailer Wiring Tester

This UHANBUT tester diagnoses trailer lighting faults on standard 4-pin flat connectors. It plugs directly into the vehicle or trailer socket to verify tail, brake and turn-signal circuits. Bright LEDs show which circuit is live, removing guesswork from roadside checks. The ABS body and copper terminals resist corrosion for repeated use.

Tow-vehicle owners and trailer renters

Ideal for anyone who hooks up a 4-pin trailer and needs instant confirmation that every light works. Not suited for 5-pin, 6-pin or 7-pin round connectors, so owners of larger trailers with electric brakes or auxiliary power must use a different tester. The single-piece design means no spare fuses or replacement leads are included.

Plug-and-play installation

Insert the male end into the vehicle socket and the female end into the trailer plug, or test each side independently. The only common issue is corroded or bent pins on the vehicle or trailer side preventing full contact; cleaning the pins before testing restores reliable LED indication. The dust cover protects the tester between jobs.

How it compares

Measured against everything we stock in Multimeters & Electrical Testers, at today’s prices. Recalculated every night.

Price $17.99
Cheaper than about 87% of the 971 comparable items (median $30.99).

Specifications

Product
Brand nameUHANBUT
Product type4-Way Flat Trailer Wiring Tester
Size & build
Overall height2.23 L x 1.32 W x 1.32 H inches
Overall width2.23 L x 1.32 W x 1.32 H inches
Overall length2.23 L x 1.32 W x 1.32 H inches
More details
Team affiliation1 Piece

Questions about this item

What connector on my vehicle must match the tester's 4-pin flat interface?

Your vehicle needs a standard 4-pin flat trailer connector for the tester's male and female plugs to engage and read the circuits.

Will the tester work if my trailer still uses older incandescent bulbs instead of LEDs?

Yes, the tester checks circuit continuity and voltage presence, so it functions the same whether the trailer lamps are incandescent or LED.

How do I confirm the tester shows all circuits are healthy after I plug it in?

When every circuit is working, all of the tester's LED indicators will light up at once.

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