What is this electrical part? M116a3

First and foremost, I tried doing a search but nothing came up that was useful. Perhaps I used the wrong keywords.

Anyways, can someone tell me what part this is on my m116a3 and what does it do?

Ive just converted to 12v(bulbs) and added a 4pin.

I have checked continuity from the 4pin all the way back to the tail lights and everything rung out correctly but for some reason, the trailer lights only work 100% correctly when my civ truck is started. When my truck isn’t started the trailer lights act like there is a voltage loss and over time(a few mins) dim out eventually stop working altogether except for running lights.

Im thinking maybe this circled part in the photo could be the issue? TIA

As far as I know there's nothing special about that molded block, it's just where the wiring changes to the individuals from the wrap.

Sounds like a ground issue. Check all grounds and make sure your hitch to the truck is clean and free of rust. Trailer might not be getting a ground from truck.

There is one wire from the rubber block that goes to ground. That one would cause this problem.

I will double check all grounds. Thank you guys! I’ll report back.

It’s gotta be a ground issue. Now all of a sudden, no running lights, just these

What are you towing with? How are the lights wired- 4 flat, 7 round, military plug? Those bottom lights are blackout and with a civy truck, would not come on. Shoot pics of your wiring set up? Might just not have the wires id correctly?

juanprado said:

What are you towing with? How are the lights wired- 4 flat, 7 round, military plug? Those bottom lights are blackout and with a civy truck, would not come on. Shoot pics of your wiring set up? Might just not have the wires id correctly?

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Towing with a 2016 Toyota 4runner - 4flat

ill grab some photos in the morning when I double check the wiring. I didn’t get a chance to check for ground issues yet.

I agree about it sounding like a ground issue. Remember that connections can be partial, too, even grounds. It's not YES or NO. Like a woman, it can be MAYBE, which sometimes means yes, and sometimes means no, and sometimes means something undecipherable. Sound familiar?

Did you ever get this sorted out?

4th wire (white) is ground, use it.

MarcusOReallyus said:

I agree about it sounding like a ground issue. Remember that connections can be partial, too, even grounds. It's not YES or NO. Like a woman, it can be MAYBE, which sometimes means yes, and sometimes means no, and sometimes means something undecipherable. Sound familiar?

Did you ever get this sorted out?

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Hahahahha

sorry, yes I did.

When switching to a 4pin my dumbass grabbed the wrong wire while ringing/labeling ground. So what I ended up labeling ground at the 4pin end wasn’t what I had labeled at the opposite end. Haha. Simple fix.

I did however notice that the passenger side (either running light or turn signal - can’t remember right now) also rings to ground. Is that normal? The lights work 100%.

Traveltocamp said:

I did however notice that the passenger side (either running light or turn signal - can’t remember right now) also rings to ground. Is that normal? The lights work 100%.

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You need ground at every light.