Tips & Suggestions for Rewiring my Trailer

[l008com]

My trailer has a relatively new connector plug (flat-4) and new lights. But the wiring itself connecting all these parts is as far as I know, original mid-80's copper. It includes a lot of basic plug connectors that go underwater all the time. I'm starting to have issues with that old copper corroding. And as always, I'm having issues with my grounds corroding.

So I'm coneplating just re-wiring the whole trailer. It's not that big a trailer so it's not that hard to do.
If I do this, I am DEFINITELY going to run a ground wire too. No more grounding to the frame, with self tapping screws that rust and corrode away.
One thing I've noticed that quality, durable flat-4 connectors don't seem to exist. Every harness I've seen has had small flimsy connectors with wires that feel like there's going to bend and snap off after a few uses. I trailer my boat so I connect and disconnect my trailer a lot, I'd love to find something a bit more durable than most.
But I guess most importantly of all, there's going ot be a lot of splicing going on here. What I've done in the past is use butt connectors and then heat shrink over that. But some of those connectors have had issues. What is the best way to make a super long lasting connection that is water proof and lasts forever? I'm going to have some three way connections if I'm going to make my own ground wire for this harness, i'm not sure how I can seal up a spliced connection like that. Any ideas? (do they make trailer harnesses with a ground wire? I haven't found any but that would be ideal)

 

[Scott Danforth]

use heat shrink tubing that is epoxy lined to be water proof, not the cheep stuff you get at most stores.

you are over-thinking the ground wire. take a 50' or 100' spool of trailer wire with the ground in it. run one length down both sides, just dont use the one signal wire on each side. splice them together at the 4-pin flat plug

 

[Patfromny]

I think what Scott is saying is to run a complete set of harness wires down each side of your trailer and use these wires for ail lights and side markers. Then make all splices up at the plug where the harness is never or rarely submerged. The ground wire is the white wire on the harness and isn't long enough to run the length of the trailer so you will have to splice in more wire for that. I would still use the trailer as a ground to be sure but if you connect all grounds To the white wire you should also be grounded by the car side of the harness. Just follow the car harness ground wire back to where it is grounded to make sure that is a sufficient ground. You could solder all splices and shrink tube those connections. Use more shrink tube than was there. A longer piece I mean so there is more shrink tube gripping the wire. When I rewired my trailer I attached string to the ends of each wire and pulled the old harness out. This pulled the string to the front of the trailer and I then attached the new wire to the string and pulled the new wire through the trailer to the back with the string. Make sure you attach the side markers to the wire that supplies steady power to the tail lights. The other wire controls the brake and directional function. Good luck.

 

[dingbat]

Saltwater boater corrison is a huge problem for me.

First off, solder and heat shrink tubing have no place in trailer wiring. I use nothing but Ancor Marine crimp connectors. Crimp, melt and the connection will still be solid when you replace the wire 10 years later.

Probably over kill for you, but I suggest installing a termination box on the tongue. Makes it easy to connect multiple wire connections to the plug. accessible "test points" makes for easy trouble shooting. Makes converting plugs ( 7 to 5 pin) in an emergency a breeze.

 

[minuteman62-64]

My boat is exclusively salt water. Re-wired the trailer about 6 years ago and haven't had any problems.

I kept all of my connections above the water line. Still used the glue filled heat shrink tubing and followed up with a couple of coats of that liquid electrical tape. Grounded the white wire to the trailer frame plus ran white wire down each side for a hard wire ground for all the lights.

​I have not re-installed the side marker lights (don't use my trailer at nite, so hasn't been an issue yet). When I do, it will challenge my practice of keeping all connections above the water line - but I'm thinking the sealing shrink tube plus the liquid electrical tape will do the trick if necessary.

 

[thumpar]

When I did my old trailer I got a complete kit. I cut the old wires and taped the new ones to pull them through the trailer. It made fast work of it. For connecting wires I solder and heat shrink everything.

 

[Scott Danforth]

I soldered and heat shrunk everything. I run 4 wires down each side of the boat, and I pick up a 5th wire (reverse solenoid) at the plug on my rig. I have a splice where the side running lights are, that splice is encapsulated in epoxy and covered in epozy lined heat shrink. I dip in salt and brackish water I also hose the boat and trailer off with every outing using salt-away, then I spray WD40 on the springs and suspension parts

 

[mla2ofus]

The liquid electrical tape is awesome stuff. I've put 3 coats on power tool cords where the sheath cracks coming out of tool handles and so far it's working well. I think a couple of coats on soldered tlr connections would hold up well.

 

[airshot]

Just like thumper I get the harness already made and pull it thru with the old harness. Another trick I use and has worked very well is get to your hdwe store and get what looks like a syringe filled with grease. There is no needle but just a narrow long plastic tip. Add your shrink tube over the connection, then squirt a small amount of grease inside the shrink tube then shrink as normal and the grease acts as a sealer. Used this for years without issue. If you do have a connection that is a slip on connection, buy a tube of Dow Valve lubricant which is a very heavy silicone grease and smear it all over the slip on connection. This silicone grease will not wash off and protects the connection from corrosion.

 

[Bkok33]

Agree with what people say about getting the harness kit and pulling the new one thru with the old harness. Will have to look into the liquid electrical tape when I redo my wiring on this trailer.