Trailer wiring issue

[svk]

Trailer wiring is always a good time. Luckily this one was easy.

Every trailer I used wasn't getting power to the drivers side turn signal. Fuse was fine, and power at the coupler. But no power at the light.

Finally figured out that the connections in the coupler had corroded to the point that the male pins weren't actually contacting the female socket even though it appeared to be clean, bare metal after I cleaned it.

Bought a new coupler and we are back in action!

You can see the metal lost, especially in the middle one.

 

[CaseyForrest]

dieelectric grease is your friend with trailer plugs.

 

[olyman]

Trailer wiring is always a good time. Luckily this one was easy.

Every trailer I used wasn't getting power to the drivers side turn signal. Fuse was fine, and power at the coupler. But no power at the light.

Finally figured out that the connections in the coupler had corroded to the point that the male pins weren't actually contacting the female socket even though it appeared to be clean, bare metal after I cleaned it.

Bought a new coupler and we are back in action!

You can see the metal lost, especially in the middle one.

View attachment 593734

at napa,, and probably others,, you can get a cover for that,, when not in use.......and a 22 cal brush will clean the contact area..

 

[muddstopper]

Had similar issues this week on boat trailer. Spent half a day thinking I had a bad bulb. Then noticed frayed wireing. Fixed the wire and couldnt get lights. Um. no power at the truck. I had one of those adapters from rv plug to 4wire trailer plug. thought adapter was bad. Then couldnt get power out of truck plug. Finally decided to just replace plug on truck with one of those combo outlets so I wouldnt need the adapter any more. Climbed under the truck to unhook wires and found the factory plug had came undone where it comes out of the frame. Half a day on a five minute fix. I went ahead and changed out the receptical anyways and now have a connection that will except the RV, 4 wire or 5 wire plug.

 

[svk]

at napa,, and probably others,, you can get a cover for that,, when not in use.......and a 22 cal brush will clean the contact area..

The covers fall off over time.

It's not cleanliness. The metal has corroded to the point that the inside diameter of the socket is too large to touch the male pin.

 

[Ryan'smilling]

dieelectric grease is your friend with trailer plugs.

Fluid Film is a great product to use in this application. @svk, if you aren't familiar with it already, I highly recommend it. I found out about it on tractorbynet and use it for everything now. It's dielectric, it's a great lubricant, and it's non-toxic, being made of lanolin. Since I am growing veggies, I love being able to use it on my ag implements and tractor linkages instead of an oil can. So, basically, I buy it by the case and leave a can everywhere. On both tractors, in the truck, in the jeep, all the buildings. It's great on trailer connectors. Definitely worth trying.

 

[Jere39]

Finally gave up trying to diagnose my problems between bad ground, busted lenses, crushed wire. I splurged on a new trailer harness, got my son to assist in tipping my trailer up on its side and completed the rewire in no time on the comfort of a stool. I pretend I am working smarter, not harder.

 

[muddstopper]

At work, we used to have mancamp trailers. Trailers with nothing but beds, shower, and a table to watch tv. We would move those trailer everywhere we worked. It never failed that on moving day you would find someone had forgot to unhook the wires from the truck and would jerk them out of the ends, or worse, rip several feet of wire out of the trailer. I wired so many new cords to those trailers, I could do it in the dark, and most times it was dark. What was really bad was when someone would rewire a truck thinking the trailer wires where right and the truck wireing was wrong. Happened more ties than I care to remember. I spent a week checking and rewireing all the trucks to standard, and then rewireing the trailer plugs to match. Lasted for one move and it was back to folks forgetting cords and yanking out wires.

 

[kevin j]

AFter years of fighting with trailer wiring, usually done by other people on borrowed trailers, I do these:
1. Run a separate ground wire, soldered to bulb sockets if necessary, not depend on chassis ground.
2. Good rubber SO cord from lights up to a terminal box just behind the hitch. If the front cord gets damaged, I only have to splice in new to the box.
3. If using a flat 4 cable on the vehicle, I wire it inside. Keep the cable clean and dry except when using, then run it under the trunk lid or hatchback weatherstrip joint and out to the connection.
4. Separate ground wire to battery, although a admit with flat 4, I often use the inside body panel and chassis ground. But sand it well, use toothed washers, and cov er it all with dielectric grease.
5. Wire the vehicle inside, if using flat 4, to a connector, then use a replacable 4 foot male to female flat 4 cable extension to get out of the hatchback. Easy to remove or replace if damaged.
6. Silicone dielectric grease packed in all connections, like the round 7 flats under bumper (the back sidew where connections are made.
6. Carry a length of wire, some crimp connectors, and a cheap voltmeter, (or at least a 12vdc test light made from soldering leads on a buld, butg I prefer tghe VOM.) in a ziplock bag.
7. Carry a 12 or 48 inch flat four extension cable. If using a borrowed trailer that is all f'd up, just cut the extension in the middle, use the VOM, and wire nut the leads together in the polarity needed to match the messed up trailer.

Really, how hard can a flat four be?
With ground on the left, ground, run, left turn, right turn. Makes easy sense,

7 pin, more room for people to get creative, but I learned with the groove in the socket at 12 oclock as most are, viewing the back of vehicle where trailer plugs in, starting at one oclock and going clock wise, 'All Right Boys Get Left Running Backwards"

1 oclock, A. Aux charge. R right turn, B. Brake. G. ground. L. left. R running. B backup center pin

 

[Marine5068]

The covers fall off over time.

It's not cleanliness. The metal has corroded to the point that the inside diameter of the socket is too large to touch the male pin.

Same on my many trailers. Not the trailer side so much as the truck side. I cleaned 'er all up and then squeezed the females tight again and then hit with dielectric grease to make a good connection for a few more years to come.

 

[Xjcacher]

Really, how hard can a flat four be?
With ground on the left, ground, run, left turn, right turn. Makes easy sense,

I've found the easiest way to remember 4 wire flat is green goes to turn signal closest to grass, yellow goes closest to yellow line and ground is white which leaves brown for ta I love lights.

 

[olyman]

Really, how hard can a flat four be?
With ground on the left, ground, run, left turn, right turn. Makes easy sense,

I've found the easiest way to remember 4 wire flat is green goes to turn signal closest to grass, yellow goes closest to yellow line and ground is white which leaves brown for ta I love lights.

nother way.. yellow, is Left....gReen,,is Right...........................

 

[svk]

My trailer lights quit working. Granted I've put about 5000 miles on the trailer in the past month which is a lot for most trailers.

Three of the four bulbs were burned out. Being the trailer light assemblies are so cheap I'll probably just throw new ones on rather than mess with ones that already are full of corrosion.

 

[kevin j]

switch to LED lights
faster light up and human eye perceives the change easier.
I want the guy behind me to be on his brakes as soon as possible when he sees my lights.
dramatically lowers the amp draw also

 

[svk]

That's a great idea for an on-road trailer. This thing gets bounced through the brush and I destroy several lights a year. I guess I could have a more protective frame welded around the lights. That's a good idea for the next rebuild of the trailer.

 

[rarefish383]

That's what I was just getting ready to say, weld a steel hoop around them. My dump trailer lights are built into a steel box/step on the back of the trailer. It's over 10 years old and I've only replaced one bulb. Seems like the smaller utility trailers with the plastic light box and two bolts are always getting ripped off or have corrosion issues. When I run new wire on a small trailer I run it through a long piece of fuel line and use heavy plastic hoop hangers every 2 feet so it won't hang down. Then I pump both ends full of a silicon sealer of flexible caulk so crud doesn't work it's way into the fuel line. That way if I drag it over rocks or logs it won't crimp or cut the line. I also run the pig tail to the vehicle through fuel line so when friends that don't know how to back up, and jack knife the trailer, won't cut the line off, Joe.

 

[H-Ranch]

My trailer lights quit working. Granted I've put about 5000 miles on the trailer in the past month which is a lot for most trailers.

Three of the four bulbs were burned out. Being the trailer light assemblies are so cheap I'll probably just throw new ones on rather than mess with ones that already are full of corrosion.

My car hauler would burn out bulbs almost every time I towed it empty. With my Jeep on it there was no problem. I figured out that the ramps rattling on the storage rack under the trailer was enough vibration to shake the bulb filament to pieces. The weight of the vehicle kept the trailer from moving as much so the ramps didn't jump around. Installing a couple of bolts to put pressure on the ramps fixed the problem - and it's quieter.

 

[moondoggie]

I chased a weird gremlin for almost two years. I all but gave up on it. I finally fixed it by mistake. I was greasing my bearings and hubs so the brake drum came off when I took the hubs off. The brakes and everything in there were covered in dust , cobwebs, and all kinds of crud. I hit all that with brake cleaner. When I put everything back together I was prepared to rewire all of the trailer lights. I purchased everything I needed that morning to rewire the trailer. To my surprise my gremlin was finally fixed.

The problem I was having: when the running lights were on my left brake light would go out completely when I pressed the brake pedal . Next problem was when I turned on the left turn signal with running lights on the running light would go out completely only on the left rear. The turn signal would still work. I figured it was a bad ground somewhere but I did not think about cleaning inside the brake drums. FWIW

 

[anlrolfe]

switch to LED lights
faster light up and human eye perceives the change easier.
I want the guy behind me to be on his brakes as soon as possible when he sees my lights.
dramatically lowers the amp draw also

Find me an LED that's DOT rated... most of the replacements at the auto stores aren't DOT rated. I love LED's and use secondary LED backup lights, secondary driving and running. Not having DOT rating could be a big liability especially if the vehicle being used has a bulb fault detector not compatible with the LED.

@Jere39
slick move tipping the trailer. Work smarter not harder.

@CaseyForrest
In my electrical world I use High Voltage dielectric grease and oil for HV cable splicing. Great for all manner of electrical wiring especially the trailer plugs. The oil gets put on the door seals just before temps drop in the fall and helps protect against frozen doors. Bad thing is that residue can stain your good cloths, not so much a problem for the work truck.

 

[Erik B]

That's a great idea for an on-road trailer. This thing gets bounced through the brush and I destroy several lights a year. I guess I could have a more protective frame welded around the lights. That's a good idea for the next rebuild of the trailer.

Would magnetic lights work for your trailer? Just put them on when driving on the public roads and off when in the bush.