Recommended 4-Way Connector for a 1996 Toyota Tacoma

Updated 03/12/2026 | Published 02/23/2026

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

(218)

$55.21

Question:

When I turn on the headlights/taillights then the brake and turn signal stops working on the trailer. I have tested the trailer on another vehicle with no issues. All brake, turn and taillights work correctly on the truck

asked by: Jamie H

Expert Reply:

Hey Jaime. It sounds like you've got a bad trailer connector on your Tacoma or something wrong with the wiring between your connector and your fuse box. A lose ground or corrosion on your connector would be the first place to look.

Corrosion can build up behind the connectors where the wires attach. I would start at the connector and work your way towards the front of your truck. You'll want to make sure that the ground wire is attached to a clean bare metal surface on your truck.

If you can't find anything obvious, I recommend replacing your Tacoma's connector with the Curt T-Connector Vehicle Wiring Harness item # C55379. This plugs in behind the tail lights and will provide you with a 4-way connector.

Does your Tacoma have a 4-way connector or a 7-way?

You can add this information, along with any other questions you have, where it says Add Comment.

expert reply by: Jerred H

C55379
(click to enlarge)

Bob

3/2/2026

You have a bad ground on the truck take a jumper cables one on the trailer and one on a very clean to the frame and see what happens take a test light and try the other 3 one is lights other are turn try turning on your 4 ways let us know how ?? it goes

Clark

3/2/2026

Hi. I've found that standard incandescent bulbs can overload some controllers. Try swapping led bulbs for your tail lights; that will likely resolve the issue and is a cheap upgrade nonetheless.

Dave H.

3/2/2026

Jerred H gave a great reply! ~ For me, the easiest thing to do is buy and install a Curtis T-connecter, plug and go. No splicing, no worries :-)

Jamie H.

3/2/2026

Yes I am having this issue after installing the Curt C55379. I have added dielectric grease to all connections and double checked the ground. Also ran a ground straight from the battery to verify that’s not the problem.

Nw T.

3/12/2026

@JamieH Just confirming you had the truck engine running when testing. I don’t remember if the instructions say that, or I missed or ignored it, but with both my 1996 and 2002 Tacomas, the trailer lights worked inconsistently with the engine off, then I tested with the engine running and have not had a problem since. I tried a separate ground and made no difference for me. Then I thought, since there is no power directly from the battery, maybe the unit needed a ‘full power’ via the lighting circuit. I suppose it’s possible there was a bad ground, but with both trucks, a few years apart, same problems, and starting the engine fixed it. Hope this helps.