Trailer Lights Gurus--Got a Question.

[npalen]

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Installed these lights on my little utility trailer and everything works correctly except the tow vehicle lights have to be on for any trailer lights to work.

That wasn't the case with the old trailer lights and everything works correctly on the pickup to which the trailer is attached.

I suspect this issue is related to the fact that the '03 Dodge Dakota doesn't have automatic lights, the switch has to be turned on manually.
I can live with this but wondering if there is a way "around it"?

TIA for any comments.

 

[sea2summit]

Sounds like a ground issue. Is it grounded well on the trailer side?

 

[CausticUrbanCoast]

Using a 7blade or 4pin connector?

 

[npalen]

The ground seems to be good.

It's a 4pin connector and everything works correctly as long as, at least, the "park" lights" are on.

I'm wondering if the light designer/manufacturer is "assuming" that no one still drives a pickup with manual lights,
(My wife tells me about all the things around our house that need "updating" Perhaps my pickup needs updating? Perhaps her husband needs updating?)

 

[Michael In Tennessee]

Do you mean brake lights don't work unless headlights are on? I'd check your truck on a different trailer and check the trailer on a different truck.

I do know newer Fords sometimes have problems with low impedance LED lights. The "smart" brake controller isn't smart.

Also, it could be ground. Run a ground wire externally to each light in turn to verify. On my trailer, I ended up with an intermittent problem. Eventually I figured out a ground problem. Its a tilt trailer and the trailer harness was grounded to the tongue and the lights to the frame. The frame/tongue pivot is old and corroded. The fix was a ground jumper at that location.

 

[CausticUrbanCoast]

The ground seems to be good.
It's a 4pin connector and everything works correctly as long as, at least, the "park" lights" are on.

With a 4 pin, no. It is not normally made that way unless you have a battery on your trailer for some reason.

With 7blade you could since it has a power supply line.

Edit: I usually switch any of my 4pin trailers to 7blade as I like backup lights on my trailers in the fall/winter or internal lights on the enclosed.

 

[nyone]

Are you sure the white wire is ground the way its wired up? Brown should be park/tail and yellow/green should be turn/brake. It sounds like your catching either a ground or power through the wrong side.

 

[npalen]

With a 4 pin, no. It is not normally made that way unless you have a battery on your trailer for some reason.

With 7blade you could since it has a power supply line.

I'm not following you here. What are you saying?

 

[npalen]

Do you mean brake lights don't work unless headlights are on? I'd check your truck on a different trailer and check the trailer on a different truck.

I do know newer Fords sometimes have problems with low impedance LED lights. The "smart" brake controller isn't smart.

Also, it could be ground. Run a ground wire externally to each light in turn to verify. On my trailer, I ended up with an intermittent problem. Eventually I figured out a ground problem. Its a tilt trailer and the trailer harness was grounded to the tongue and the lights to the frame. The frame/tongue pivot is old and corroded. The fix was a ground jumper at that location.

None of the light functions such as turn signal, brake lights, hazards work unless the pickup accessory (ignition) switch and light switch are on then all functions work correctly.

 

[CausticUrbanCoast]

I'm not following you here. What are you saying?

With a 4pin connector the taillights and signal lines are only energized when the vehicle's are.

Whatever the vehicle behavior is will be what your lights are: so if your vehicle has no markers unless the headlights are on, the same goes for the trailer