Utility Trailer - New Lights Do Not Work

[adalbert]

I just installed standard single harness lights (with a flat four connection) on my utility trailer.  These include tail lights, turn signals and brake lights.  The turn signal and brake lights only work when the head lights are not on.  The tail lights never works.  Does anyone know how I can get the tail lights plus the turn signals and stop lights to work when the headlights are on.  Thank you

[Railton]

Adalbert, Re-check wiring to wiring diagram supplied with lighting kit. Possibly hooked-up backwards, poor ground, etc. Sounds like a fiddly problem as trailer lighting can be. Does your car have auxilary connections for trailer package lighting or are you splicing in?
Railton

[tpl]

Adalbert, does your car have its tail lights on all the time, that is, does your daytime lighting set up include the tails lights?
It sound as if the ground connection you are using is in fact not ground at all but something else.

Does your car use a 2nd filament in either the brake light bulb or the tail light bulb for turn signal or a separate bulb. Clue is that if your rear turn signals are amber then it is a separate bulb.


if you are splicing in then comes a 2nd question, on the tail/brake light assembly in the car is theer a common ground wire  and a "signal" wire to each bulb or a separate pair of wires to each bulb.

It would be good to check if,with the trailer attached,that ALL the car lights work correctly and at the correct brightness.

[articsteve]

What kind of car is supplying the power.  Some need a converter.

[Railton]

..or a relay upgrade.
Railton

[adalbert]

I appreciate all your suggestions.  I rechecked wiring to diagram and it is OK and the wires are correctly ground ie. both the ground from the car and from the trailer AND the tail lights or turn lights still do not work when the car lights are on.  Following are responses to your questions:
Railton:  there is a harness coming from the car into which I am hooking the trailer plug into.  Car harness was installed by a shop that installed my trailer hitch.
Tpl: daytime lights do not have tail lights on.  Turn signals are amber.  All car lights work proplerly and with normal brightness when trailer is hooked up.
Arcticsteve:  car which trailer is hooked to is a 2002 Honda Accord.  Do you know if it requires a convertor or a relay upgrade?  Any other suggestions?

[articsteve]

OK, the shop must have installed whatever is necessary for the Accord.  Normally, when you install the usually 4 wire trailer connector to anything other than the GM or other domestic cars, it requires a converter to tie the turn signals in with the brake.

Any car that runs totally seperate turn signals will need a converter.  Example, I went to hook up a standard 4 wire plug to my 88 Cherokee and very soon clued in that I had seperate turn signals and I found a converter that I had used on a 84 BMW. So you must have a converter.  You better look behind the trunk liner or call the fools that installed it to confirm you have the converter.

What you need to do is get a volt meter and with a good ground on the car or use the odd one of the 4 connectors, check to see what each wire is giving you.  First running lights, then each turn signals.  The brake signal should be incorporated into each turn signal. That could be your problem If that is not coming thru then I would confirm your car wire installation vis-a-vis the converter.

Once that is figured out.  Hook up the running lights of the trailer first.  You need a volt meter to ascertain what is going where.

What kind of trailer is this?  

[adalbert]

Thanks for the information Articsteve.  Just got all the lights going on the utility trailer.  We just checked another utility trailer in our town and noticed that there is a ground wire going from each trailer lite to the body of the trailer.  This is in addition to the ground wire that is attached to the plug (wires from the trailer).  These two additional ground wires were not described in the wiring diagram that came with the lights - an important omission.  Thanks all for you input.  

[Drivesideways]

Thanks for the update, Adalbert.  That was a very informative exchange.

[Roadrunner]

Adalbert
Are those tail light assemblies mounted to a wood support and not to the metal trailer frame? If so, that's the reason for the separate grounds. Most trailer light assemblies are mounted to a welded frame bracket.

[adalbert]

Roadrunner - yes, they are mounted to a welded frame bracket and the bracket is welded to the frame.