Trailer lights work......sorta

[MH Hawker]

Re: Trailer lights work......sorta

you need something like this to hook into the truck wiring harness


http://www.truckspring.com/trailer-parts/trailer-wiring/trailer-wiring-connector/t-one-connector-118325.aspx


View attachment 123518

 

[hrdwrkingacguy]

Re: Trailer lights work......sorta

something has to be miswired...is it possible your green and yellow wires are feeding back through red instead of ground(on the diagram)??? Do the lights come on less bright then they should be???

What I would do is take all the bulbs out and turn on a turn signal and check with a test light to the trailer frame, then make sure you are using the right ground wire...



That is basically my right rear light it has a brown, green and a white going to it...

 

[MH Hawker]

Re: Trailer lights work......sorta

I belive you are miswired at the truck to start off with. Do you have a T connecror in the truck wire harness. A T connector is the best and simplest way. Just tapping into it with just wires can lead to all sorts of issues like you seam to be having.,You can pick up test device that plugs into the truck side of the wiring at most any auto parts supplers or other trailer parts places. Once you know the truck wiring is correct then move to the trailer

http://www.reese-hitches-online.com/t_con_search_results.htm

 

[jessper]

Re: Trailer lights work......sorta

There is a separate filament in each rear light for the turn signal and brakes. Could just be that both light bulbs in the trailer have a bad filament but the other for parking lights still work. The bulbs may have been damp or something when you hit the brakes sometime. Might be worth checking.

 

[kfa4303]

Re: Trailer lights work......sorta

I believe the filaments in both bulbs in each set of lights are fine as evidenced by their ability to turn on and shine brightly when in headlight mode. The lights are up on PVC guide mounts and have never been submerged, or wet in any way, so I don't think it's a water intrusion issue. I don't think I really need a t-connector, as the current set up has worked perfectly well in the very recent past and all of the lines are in good condition and getting current according to my LED, plug-in tester. This brings me back to some sort of an grounding issue on the trailer side of things. I don't understand how it can work in headlight mode, but not other :/ It seems like it would be an all or none sort of response (i.e. all of the light functions would work when grounded, or not) :/ Thanks again for any help.

 

[MH Hawker]

Re: Trailer lights work......sorta

Thats why it makes me think it may be on the truck end. And no you do not have to use a T connector its just a lot simpler. and a fyi , current is the amp flow , I belive you mean voltage. When trouble shooting a power issue you start at the voltage sorce ( the truck ) then work back. If the tester works right with out the headlights being on then the truck should be right, if the tester only works with the headlights on , then it is on the truck end. The diagram you are using is the standard one that that is used on most ever trailer , and yes the most common problem is grounds not making contact to the frame , and bad connections, If it is on the trailer end you have to go over ever connection point. Those testers work great I keep one in my glove box just in case I have a issue while out towing. Dont get frustrated I am around most of the day and will look back in on and off and will help you all I can I will stayed logged in here and you can shoot me a IM if you like. Their are two elements in a standard 1157 bulb one is for the running lights and will be a lower light level, turn signal/break light is the much brighter one, those often get hooked up wrong. The turn signal/break light voltage is shifted around depending depending on what function is in use from the truck and those wires being reversed on the trailer often causes problems.

 

[kfa4303]

Re: Trailer lights work......sorta

Thanks for sticking with me Hawker. The tester seems to work properly (i.e. LEDs light up only when the headlights are in use and/or when LT and RT indicators are turned on at which point the corresponding LEDs pulse in time with the blinkers themselves.). This makes me think that things on the truck side are ok??? As far as grounding the wires on the trailer is concerned, should I mount the additional, white, ground wires I have installed along with the white ground wire on the trailer side plug, to the trailer itself? I thought the idea behind running independent ground wires from each set of lights, then connecting them to the common, white, ground wire on the trailer side plug was supposed to "fix" or reduce these sorts of grounding issues, but I'm starting to think that may be the issue. I don't know why it would've worked OK in its current config., in the past, but who knows. Thanks again.

 

[MH Hawker]

Re: Trailer lights work......sorta

Yes a lot of people do add the extra ground wires, personally I have never had issues with grounds, I clean the paint off of the frame and add dielectric grease to keep corrosion down but I am only in fresh water and in salt water makes it harder , and that is the reason a lot add the extra grounds so its not frame dependent. Welcome to owning boats and trailers, I used to try and sort out a lot of those issues to save a few dollars and you can. I just find it a lot easer to buy a new light kit and harness ever few years. It seams like once you start having problems it keeps going until you replace ever thing. A kit is around 30.00 I get the submersible kits but it is often different on each trailer. And no big thing its one of the things that atracted me to this forum I fix my own stuff and I have plenty of help.

 

[GA_Boater]

Re: Trailer lights work......sorta

kfa - It's time to check your bulbs. I wonder if both brake filaments are burned out.

 

[erwinner]

Re: Trailer lights work......sorta

I just find it a lot easer to buy a new light kit and harness ever few years. It seams like once you start having problems it keeps going until you replace ever thing. A kit is around 30.00 I get the submersible kits but it is often different on each trailer. And no big thing its one of the things that atracted me to this forum I fix my own stuff and I have plenty of help.

I like it. I had a problem with mine and just swapped 'em. Worked great. Some wire had rubbed through the insulation and grounded out. New one fixed it quickly, and for $30. Buddy was backing my trailer last month, bumped a curb and broke the casing on a new one. Not so submersible anymore! Oh well, just another $30... that's just 10 gallons of gas these days!

If you've tested the truck and it's OK, I'd give the $30 to change everything and avoid troubleshooting the existing system.
Unless you're talking about some fancy or custom lights...

 

[kfa4303]

Re: Trailer lights work......sorta

Yeah, I think y'all may be right. I went out and did some more tinkering, but it didn't help much. I tried using my tester again and all of the LED indicators work properly (i.e. 1 LED on when headlights are on, 1 LED on and pulsing with each corresponding blinker, both LT and RT LED indicators come on when I hit the brakes) all that makes me pretty sure the truck side is ok, which is what I was most worried about. I also tried disconnecting the independent grounds and used the single white ground wire on the trailer side plug and c-clamped it to a fresh, bare spot on the trailer in an attempt to "simplify" the set up and keep it stock, but that didn't work either. I also took the cover off the lights to look at the bulbs and they're all fine; no scorching, or blown filaments. I was also able to get each taillight to come on independently in headlight mode by grounding them one at a time to the white ground wire on the trailer plug, so I know that the independent grounds I ran are serving there purpose and that the white ground wire on the trailer side plug is working properly (right?). I know I'm starting to chase my tail at this point, but my OCD wants to know why it's doing what it is all the same. It's no fun just buying a new kit. Id much rather beat my head against a wall for hours. Ohyeah, and I'm cheap... LOL. I guess any time you have water, metal and electricity all coming together on a regular basis these sorts of things are bound to happen eventually .........
However, just for the sake of argument and to help appease my OCD a bit, if I did have a bare spot on one wire, would that kill the lights to that side of the trailer alone, or to both sides? If so, wouldn't it do so completely such that the lights would not work at all, in any mode? The fact that both of my lights behave in the exact same manner makes me think there's just some little thing I'm missing:/ It's as if the brown wire (headlights) on each side is fine (i.e. properly grounded), but the green (RT) and yellow(LT) are not, and therefore do not function despite being perfectly in tact and having a good plug on both the truck and trailer ..............hmmmmmmmm. I'm still open to any suggestions. Thanks again one and all.

 

[MH Hawker]

Re: Trailer lights work......sorta

Buddy was backing my trailer last month, bumped a curb and broke the casing on a new one. Not so submersible anymore!

If you look around you should be able to fing just a replacment housing n bulb with out buying a complet new kit, also why I like to start out with a new set up, after awhile you cant find exact replacments it may look the same but it will be diffrent. I allways break at least one ever season.

 

[UncleWillie]

Re: Trailer lights work......sorta

I share the OCD thing. I have been known to steal an interesting piece of the neighbor trash just to see how it works. Ending up fixing it because it was such a simple problem, only to thow it back out again because it really was trash to begin with. But, at least I now know how it works. Anyway ......

When you say it works with the HEADLIGHTS, what you are really saying is that the TAIL LIGHTS work. In other words, the BROWN circuit is working. GRN and YEL are dead.

Turn on the four way emergency flashers. GRN and YEL circuits should be flashing.
Turn on the TAIL LIGHTS. BRN Circuit is powered.
Pull out the Tail lamp bulbs (1157).

Measure the voltage from the side of the sockets (GND) to the two buttons in the bottom of the sockets (POWER).
Caution: Don't short them out.
One should be a constant 12volts. The TAIL LIGHTS. (BRN)
The other should be a pulsing 12 volts. The GRN/YEL circuit. Brake/Turn/Emergency Flashers.
Depending on you meter, you may get silly readings with a pulsing voltage. Anything less than 2 volts is same as dead. Jumping all over the place is flashing 12v.

If it is pulsing, you have bad bulbs.
If it is zero, start working back up the wiring to find the open.
If the emergency flashers go dead on the vehicle when you attach the trailer, you have a short.

Happy hunting.

 

[kfa4303]

Re: Trailer lights work......sorta

Thanks Uncle Willie and welcome to iboats. Hopefully, I can figure it our, one way or the other, so future readers of this thread can benefit from it. I'm sure I'm not the first guy this has happened to. I keep coming back to the idea that the YEL and GRN wires just aren't grounded somehow......do they/should they share a common ground at some point, perhaps in the the trailer side plug itself? Just making a wild guess....I'll give your suggestions a shot and let y'all know what I find. Thanks again everyone.

 

[Bondo]

Re: Trailer lights work......sorta

Thanks Uncle Willie and welcome to iboats. Hopefully, I can figure it our, one way or the other, so future readers of this thread can benefit from it. I'm sure I'm not the first guy this has happened to. I keep coming back to the idea that the YEL and GRN wires just aren't grounded somehow......do they/should they share a common ground at some point, perhaps in the the trailer side plug itself? Just making a wild guess....I'll give your suggestions a shot and let y'all know what I find. Thanks again everyone.

Ayuh,.... If they're grounded before the lights, it's called a Dead Short...
You also won't have blinkers, 'n brake lights...

There should be No grounding, til the light that's being lit...

 

[kfa4303]

Re: Trailer lights work......sorta

Ah ha!!! I think you may be on to something Bond-o! My plug-in tester says everything is working just fine on the truck plug, so I'm pretty sure that side is ok. However, I only have headlight/taillight functionality in the trailer lights at this point, but no brake or turn signal function, as you described. Where might I look to see if the YEL and/or GRN wires have a "Dead Short"? Thanks again everyone.

 

[Bondo]

Re: Trailer lights work......sorta

Ah ha!!! I think you may be on to something Bond-o! My plug-in tester says everything is working just fine on the truck plug, so I'm pretty sure that side is ok. However, I only have headlight/taillight functionality in the trailer lights at this point, but no brake or turn signal function, as you described. Where might I look to see if the YEL and/or GRN wires have a "Dead Short"? Thanks again everyone.

Ayuh,... At the light end of the yellow, or green wires, you should have Power,...
Test it with a test light, or multimeter...
The yellow, 'n green wires go to the brighter filaments in the bulbs...

 

[UncleWillie]

Re: Trailer lights work......sorta

Just so we have not made any false assumptions. What is the number/Type of bulb on the trailer?
I just looked at one that uses the 3057 bulbs, a modern cousin to the 1157 classic bulb.
The 3057 has seperate grounds for each filament. Thats a horse of a different color.

Also, are you certain both filament work in each bulb. Looking at them and saying that they are good does NOT count.
Get a piece of wire and touch then to a battery and actually light the filaments!!!
If you have not actually seen them light you can not say they are good.
The filament that are not working are the brighter of the two, and are the ones most likely to go first.

Also(2), Can you use the tester and the trailer at the same time?
May of the testers have a cover that come off to expose the trailer connector along with the vehicle connector.
If you have a short you may have blown the turn/brake combiner in the tow vehicle.
The tester may still show good, it will light with less that 5 miliAmps.
The bulbs will need a few hundred. The Taillights do not go through the combiner, so would still be fine.
Bulbs actually light using the CURRENT(Amps) produced by the VOLTAGE. (Important: Read that again!)

We are still waitiing for the results of your meter readings.

Bill.

 

[UncleWillie]

Trailer lights work......sorta ... Epiphany

Trailer lights work......sorta ... Epiphany

OK, I have thought this through. Let's apply Occam's Razor!
You either have two bad bulbs, Two bad wire runs, two bad Lamp assemblies, or a combination of any or all.
Or ... you have one problem that is common the both left and right, brake and turn circuits. And the answer is .....

You have/had a short in one of the Green or Yellow circuits and blew the fuse to the Brake/Turn combiner module in the Truck.
You do not have 12 volt power to the Brake/Turn combiner module in the truck.

I can hear you saying, "But the Tester shows it is good!"

You may not understand this but others may, so here goes...
The electronics in the combiner are working to mix the Brake and Turn lamp signals.
This signal will be fed to the Base of the final drive transistors.
The Collectors are floating because of the blown fuse.
The Trailer is connected to the Emitters of the drive transistors.
The Base/Emitter current IS enough to light the LED's in the tester. (You are getting a false positive.)
The Base/Emitter current is NOT enough to light the actual Brake/Turn Lights.

In simple terms, the power from the truck's Brake/Turn lights is leaking enough through the combiner to light the tester but not enough to light the actual lamps.
The Tail light power is not involved with the combiner, so they work just fine.

You have never confirmed that the truck will actually power a known good trailer.
You have only used the tester. (Trouble shooting Rule#2 = Keep asking yourself, "Is my test equipment lying to me?")

How to confirm it?
1. Hook up a known good Trailer. Or ...

2. Turn on the Tail lights and the emergency flashers on the truck.
Hook a test bulb from ground (WHT) of the Truck connecter to each of the other three pins (BRN/GRN/YEL).
If all three do not light the lamp, the problem is in the truck.

Remember: Bulbs actually light because of the CURRENT(Amps) produced by the VOLTAGE. (Voltage x Current = POWER!)
Example: Two 9 volt transistor batteries hooked together will produce 18 volts. Plenty more than the truck needs to start. But they will never, ever come close to starting the truck.
Why? Plenty of volts, but no current capacity. It takes both. No current, No power!

Happy Hunting!

 

[cyclops2]

Re: Trailer lights work......sorta

Love that electronic combiner.

Combines a lot of possible problems in a trailer. :facepalm: