Some ID help on parts in trailer hitch

[Tom7227]

I have a bunk trailer that has 4 wheels.  On the hitch there is a chain that goes to a cable that goes into the front part of the hitch.  I think it's a deal that is supposed to activate the brakes if the trailer breaks loose from the truck.  Right?

Then on the side there is a short cable that goes to a T shaped piece that fits into a slot on the side of the hitch.  That piece won't stay in place and so I have to tape it to hold it there.  There also is a pin on the cable that I presume is for me to put in the lever that holds the hitch to the ball.  What is the T shaped piece for?  Why do I have to hold it in place with tape?  How is it supposed to work?

Finally the trailer is wired for a five prong electric connection.  My truck, a 14 F150, only has a connector with 4 prongs.  I don't know what I am supposed to do with that.  I came up with a jumper that only has 4 prongs and use it.  Any explanation?

Thanks for your time.

Tom

[HD]

I only have a couple answers to your questions.
Yup the chain to the cable is for, and if the trailer becomes detached from the truck to apply brakes.

I don't know about the t bracket without seeing it.

And yes, you can get an adapter plug to go from the round prong connection to the 4 prong (straight) connection. If this is what you are talking about... without seeing pictures, I'm just guessing.

[Boar]

HD IS RIGHT, the cablebconect to a pin typT that when pullednout engages the trailer breaks, generaly the is a small 12v bbat. like a vexilar battery that powers the system and that needs to be charged from time to time. and yup you can ge the right adaptor at any parts store and also help yu with understanding the system

[Gunner55]

BIL has a double axle 6,000 # trailer that they use to haul their 4 wheelers(3) up to the lake & from what I've seen of his brake system, HD & Boar are spot on. He uses the adapter on his as well but his little battery is getting old & was in need of a charge when they came up this season. So he's going to get 1 as a gift this year.