So one of the metal prongs on my trailer connection for my lights broke. I ordered a new one with 18 inches of wire that’s coming in 2 days.

 

I’ve done some research and looked at you tube but hopefully some great electrical mind can confirm that this is what I need to do.

 

I stripped back the plastic covering on each individual wire (1 yellow, 1 green, 1 white, 2 brown) so that the copper is exposed. I need to cross the exposed copper with the end of the copper wires I ordered, twist them together, and apply a waterproof coating with a mild heat source.  I attached a photo for reference and you can see the missing metal prong.

 

Is this correct?

That connector is toast so just cut it off close to that connector. Use crimp splices to new connector and you are back in business.

 

 

2 minutes ago, FloridaFishinFool said:

Just cut it off close to that connector. Use crimp splices and you are back in business.

 

Thanks.  I cut it about an inch from the connection point.  

 

Is the rest of my process correct?  I've never done this myself.

For now sure. You have peeled back enough of the outer insulation to access the wires and have enough exposed to make the new splices.

 

When dealing with crimp splices you don't want to crimp too tightly because you can mash cut through the wire. Or, crush it to the point a couple of bends of the wire and it breaks off. Crimp just enough to make tight connection but not too tightly that crushes or damages any wire. Check them by pulling straight out on wires. A good crimp will stay in place. A not so tight crimp and the wire slides out. Redo.

 

I like to double up the wire going into the crimp because of this. When you strip back the wires, go about 1/2" and twist wires some to form a more solid wire and fold it over so you have a double sized 1/4" exposed wire to slide into crimp splice.

 

ADDED: You have 5 wires going to that connector. It is the single wires I would fold over double if you can fit that into the splices you buy for the white, green, and yellow wires. The two brown wires can be twisted together with 1/4" wire exposed for sliding into the crimp. The two wires makes double anyways. The reason I prefer to fold the wires over for double size going into a crimp is because it doubles the surface contact area, and may make a lower resistance connection because of the additional surface contact area, but it also provides twice the material to crimp down on for a better grab on the wire with slightly less possibility of over crimping too tightly and damaging wire leading to breakage down the road.

 

I like to use a wire treatment to prevent corrosion. And it would be a good idea to use heat shrink or tape it up good once done to try and prevent any shorts and help keep the wires from bending at the crimp joint.

 

This does not have anything to do with the connector you are working on, but on the trailer wiring. I stopped using the frame for the ground or negative connection to lights and took an old 50 foot household extension cord and cut it in half and ran half to lights on one side and half to the other side. Larger wire with better doubled up insulation. I now run the ground or negative directly to the lights through the wire and never have any trouble with my lights ever.

 

Usually the screw to the frame near hitch causes a bad ground connection, or the screw connections to frame at the lights eventually makes a bad faulty connection. Running ground wires to the lights has solved that issue for me. Just a suggestion.

 

I'll bet you the wires on the new connector are not as heavy a gauge as the wires in your harness now.

 

***Just saw the photo below... he's on the same page.

I personally use heat shrink butt-splices for all my wire-to-wire marine connections.

Available at Home Depot - pink is 18-22 gauge

Each stripped wire goes halfway in, crimp them down, then apply heat to shrink down the ends to seal it.

Not sure what crimper tool you have, but a lot of people use a flat crimper like this:

 

 

The above crimper is designed to prevent over crimping, but sometimes may not be enough because its just an almost flat crush. These types of crimps may not be as durable as other methods with different shapes of crimping.

 

Some people will side shift a crimp in the above tool once they have gone as far as they can with the almost flat crimp, and side shift to a point centered on the crimp for extra crushing pressure beyond the designed limits of the tool.

 

There is the standard electrician crimper which is designed to have a point pushing in on the crimp backed by V shape channel shape to really give it that centered deeper crush point. These are the type of crimpers you gotta be careful with that you don't over crimp with them:

 

 

 

Looks like an electrician has done some shorting out of live wires with this tool. I count at least 4 arc burn spots is what it looks like to me. But if one were to crank down with the above tool you can crush cut crimps and wires in half by overdoing it.

 

There are all sorts of tools available. Just make sure to not over crimp.

 

9 hours ago, MN Fisher said:

I personally use heat shrink butt-splices for all my wire-to-wire marine connections.

Available at Home Depot - pink is 18-22 gauge

Each stripped wire goes halfway in, crimp them down, then apply heat to shrink down the ends to seal it.

This^^^
 

Pretty much every auto parts store and hardware store has them. Saves lots of headaches down the road. 
 

Some even have a low temp solder in them that melts and flows with a bic lighter, making your connection that much better.

another for the heat shrink splices.  That's what I used in the kayak for almost all of the wiring.  So long as you get the right size and go gentle with the heat (just enough to shink the tubing and melt the solder, but not enough to melt the tubing) they lock up tighter than anything and are waterproof.  And is is a soldered connection which is better than just a contact connection.

What I like to do is cut each of the wires an inch longer than the next one so the crimps aren't touching.  Instead of shrink tubing, which isn't fully waterproof, use RTV inside each crimp to seal it.

Alex and casts_by_fly, I live in one of the worst states for water and corrosion- Florida. Its bad here and worse on the coasts.

 

What I am getting at is that waterproofing these splices is not a good idea because for one we never really waterproof anything. Water can and will get in. What I believe we should prefer is that when water does get in we should want it to also get back out.

 

Trying to seal up these connections from water is a mistake in my opinion because we are not keeping water out. We are in fact keeping water in there. And that is where the long term damage comes from.

 

I would like to point out there is really no reason to try and waterproof these connections because this part of the trailer never goes underwater and 12 volts can be submerged.

 

I am an old service tech. I want my trailer and lights to be field serviceable. So I do not use splices. I use plain old wire nuts. And I turn them up so the water can drain out of them and dry out. And I spray them from time to time with a corrosion inhibitor and I can fix and repair all of my trailer connections on the fly with almost no tools so long as I do not have to cut wires or strip them. I can remake all my connections at the front and rear of the trailer instantly. Twist on twist off. Piece of cake.

 

All of my 12 volt light connections at rear of trailer are fully exposed to the water I back my trailer into. Even with the lights on they work just fine underwater because the voltage is so low and resistance in the water is high enough to cause no issues for short term exposure.

 

Try fixing splices on the fly at a boat ramp when you need to drive home in the dark with no lights working.

 

I did not recommend this for those front connections above because splices will work just fine if done right. All they need to do is make sure they are electrically insulated and that's it. Trying to waterproof connectors seems like a good idea, but is it really necessary? Not if that same effort keeps water inside those splices 24/7 and won't let it dry out. That waterproofing effort may actually speed up the corrosion process.

 

I agree staggering the splices is a good idea. But waterproofing? I'm not going there any more. 13.8 volts can get wet. Its the drying out I really need.

 

 

My lights last for a few years with me launching several times a week in Florida for 4-6 months of the year.  Even in salt water a few times a winter.  I use the potted LED lights which last even though the lenses are broken.  BTW I agree with the draining if needed.

22 hours ago, MN Fisher said:

Each stripped wire goes halfway in, crimp them down, then apply heat to shrink down the ends to seal it.

I have some of these. So I don’t need to actually twist the copper ends together using them? Just heat up the middle part where the metal is and it’ll naturally “connect” the copper ends together?

4 minutes ago, gim said:

I have some of these. So I don’t need to actually twist the copper ends together using them? Just heat up the middle part where the metal is and it’ll naturally “connect” the copper ends together?

I'd still twist for easy/neat insertion. If they're a crimp-solder type, then yes...crimp them first as the solder isn't enough to fill the gap, just to make the connection more secure. Also, too much heat will evaporate at least some of the glue that's coating the inside of the shrink tube, making it not quite water-tight.

On 8/20/2025 at 11:18 AM, FloridaFishinFool said:

Water can and will get in.

I respectfully disagree. If done correctly, splices or virtually any electrical connection can be made waterproof. Adhesive lined shrink tubing  is best to use and if one wants to go one better, using a self fusing silicone (IIRC) tape around the connections.

 

Case in point - 7 years ago I installed  a new 7 blade towing adapter in my rear bumper and wrapped the rear of the adapter with the self fusing tape. Fast forward 7 years and the rear bumper rusted through and required replacement. I dreaded having to remove the towing adapter figuring if the bumper had rusted through, the connections on the adapter are going to be toast. As luck would have it, once I cut away the tape, the connections were pristine just like when I first installed it. If any water was to get in and even if it could drain away, those connections would be a mess.

 

Another tip would be to use Ox-Guard (Lowes) on the wires before crimping to prevent corrosion and improve conductivity. I've also heard that soldering connections in a high vibration environment is less favorable that a crimped connection. I can't confirm that but I'll use crimped connections in those situations.

 

If water is allowed to enter the connection and drain out, it still is possible that some water can "seep" into the strands and get trapped within the wire itself. I have had occasion to find a seemingly good wire actually be corroded internally without any indication of this on the outside.

 

Another option would be to use Posi Lock connectors. Any future replacements would only take minutes and not require any tools. They are available at most automotive stores.

 

I'm not an electrician or an electrical engineer, but I've done quite a bit of automotive wiring. Photo of my Samurai featuring a lot of wiring and other mods...

 

@Crow Horse thanks for the information.

 

I’ve never done this before, so it’s going to be trial and error.

11 minutes ago, gim said:

I’ve never done this before, so it’s going to be trial and error.

You've got this and you'll see how easy it really is. The key is to match the colors and have the correct hardware for the connections. Easy peasy!

28 minutes ago, gim said:

@Crow Horse thanks for the information.

 

I’ve never done this before, so it’s going to be trial and error.

You got any issues - I'm close and can come give you a hand.

Update.

 

I received the new 4 way/5 wire replacement today. I twisted the copper wiring together, slid the connectors over top, and applied some minor heat to seal. Then I taped the entire section with electrical tape to hold it together good.

 

The trailer lights are working again. I learned something new today, on my own.

23 minutes ago, gim said:

The trailer lights are working again. I learned something new today, on my own.

It's always nice when a plan comes together....and actually works. Well done!

I always unplug lights when launching/loading, that way they never get submerged and I don’t have to heat shrink anything 

 

it also extends the life of my bulbs not being hot and wet at the same time. 

7 hours ago, TnRiver46 said:

it also extends the life of my bulbs not being hot and wet at the same time. 

 

I used to do this on our family boat years ago because the bulbs were incandescent versions that heated up when in use.

 

Modern bulbs are LED and do not have issues like that.  My trailer lights are all LEDs.

12 hours ago, gim said:

 

I used to do this on our family boat years ago because the bulbs were incandescent versions that heated up when in use.

 

Modern bulbs are LED and do not have issues like that.  My trailer lights are all LEDs.

Yeah I tried that, smashed the $50 LEDs on a log in the water. I’m back to the $8-$12 incandescents now 😂 

Wouldn't it be more of a consideration if the lights are submersible or not, irrespective of them being LED's or incandescent?

1 minute ago, Crow Horse said:

Wouldn't it be more of a consideration if the lights are submersible or not, irrespective of them being LED's or incandescent?

Incandescent are not submersible regardless of what the package says (and regardless of a bead of caulk around the seems)

LEDs work when wet