Trailer Wiring Tester Tips (Canada)

Plugging a trailer harness into the vehicle connector at dusk
Trailer wiring

A plug tester shows which circuits are live at the vehicle or trailer connector. Use it before you replace lamps or harnesses so you stop guessing.

4 Way Connector Tester
4 Way Connector TesterCURT 58260$19.13 CADSee the part →
We stock CURT towing gear for this job, with free shipping anywhere in Canada. Prefer the full library? Open the towing guides hub.

How to use it

Plug the tester into the vehicle socket, then step on brakes and signal. Lights on the tester should match. Repeat at the trailer plug if you have an adapter for that test.

What it tells you

Dark pins point upstream to fuses and grounds. Good vehicle pins with dark trailer lamps point at the trailer harness. Keep a tester in the glovebox for Canadian roadside surprises.

Parts we commonly sell

Confirm ratings and fit notes on each product page before you order.

Official CURT context

Official clips from @curtmfg. If an embed stalls, use the YouTube link under the video.

How to Select a Trailer Hitch

CURT · Official overview

Classes, receiver sizes, and matching hitch ratings to the trailer.

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Trailer Wiring Basics

CURT · Official overview

Four-way and seven-way habits before you order a harness.

Watch on YouTube

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