Trailer light problems

[Cicada]

I have been having problems with my trailer lights. I put new rear lights on. I don't get lights or turn signals when the headlights are on. The little strip between the lights on the rear do light up when the headlights are on. I do get turn signals as long as the headlights are off. Checked the little yellow lights on the side of the trailer and they are ok. I have a Ford Ranger with their adaptor plug and I have power coming through it. Any clues on where I should go from here? The polite way to put it is that I am befuddled.

[EBass]

Crazy - and I thought I went through all the trailer wire issues there could ever be.

#1 Check the ground

#2 Check all the new connections you made

#3 At Gander or where ever they make a tester that plugs in lights up/or not and then you can see if it's the trailer side or the truck side, then go from there.

[Cicada]

I'm assuming it's not the ground since I do have turn signals when the lights are off and the little strip of three lights between the rear lights light up when the headlights are on.

I checked current in all the posts of the pigtail at the truck. Tester lights up properly there. I have current to the side lights, but they don't light up when the headlights are on. I pulled them and hooked them directly to the battery and they do work.

[Ralph Wiggum]

Do you have it grounded through the plug, or are you relying on the hitch for a ground?

[CatchPhotoFilet]

I think you might have the wrong plastic connector that you plug into you truck. If your truck has those round connectors that plug into it look at a different style one. I had that problem on my boat when I bought it. I had the wrong female connector end that plugged into the tuck so it made it work but incorrectly.

[Cicada]

When I tested the pigtail from the pickup, I hooked the ground to the pigtail. When I tested the lights at the end of the trailer, I used the ground wire back there.

When I got the trailer last year, the lights worked correctly.

The connector is one of those in-line hookups for the Ranger, so it is a flat, four wire hookup.

[Determan]

Not trying to be sarcastic, but I remember reading an article in an outdoor magazine years ago about trailer lights.

The article started out "20 million years ago man invented the wheel. Shortly after he invented the trailer, and he has been trying to get the lights to work ever since."

[Cicada]

Any other day, that'd be funny right there

That's why I went with LED lights this time. I had them on my last trailer and they were flawless until I traded for this trailer.

[catfishhunter]

I've had issues like this before, Check the fuses in the truck for the trailer lights, you might find that there are two that control the lights and that one is shorted, Good Luck, Yes trailer lights can be a bummer. Tip... Unplug them before backing into the water. Hope this helps.

[Cicada]

Fuses, check. They all look ok.

The only thing I haven't checked is the brake lights. Judging from my avatar piture, you can assume I'm not quick enough to push the brake pedal and then run back thee to see if they're on.

[Black_Bay]

Double check the ground just for grins. A bad ground will make the lights do all sorts of odd things.

[marine_man]

You've validated that the pigtail coming from the truck is good, with power at the brown terminal when the taillights are on, and power at the yellow and green when the taillights are on, and you have a left or right run signal (or hazard lights), correct?

marine_man

[Cicada]

marine_man- checked the pigtails at the truck again. I have light when the headlights are on, and turn signals along with the headlights when the headlights are on. To check this I connected the ground clamp to the ground post on the pigtail.

Am I correct in assuming that if you get a light on the tester at the back of the trailer, the ground is ok? Would it light up if the ground was goofy?

[Phred52]

Cicada, To isolate if the problem is in the trailer wiring or the tow vehicle is quite simple. If you have a spare 12volt battery handy, to an UNHOOKED from the tow vehicle trailer connect the - to a clean ground on the trailer. Using a probe (a 16d nail works very well) hook the + to the nail and then the nail to the Brown wire connector on the plug. That will be your tail and marker lights for the whole trailer. They should ALL light, if not determine if you have a burned out bulb or a bad connection. Then connect to the Yellow wire, that's your Left (drivers side) blinker and the one that controls your brake lights. They should all work, if not check those connections. Finally, the Green wire. That one is the Right directional signal. Pretty simple, That will eliminate the connection at the tow vehicle and you know the trailer is all working and correct. One important note!!! DO NOT CONNECT THE PROBE TO THE WHITE WIRE!!!! That's Ground and it will short the circuit!! You'll learn just how fast wires can melt!!Phred52

[Cicada]

Thanks, if it warms up today, I'll try this.

[Cicada]

It is in the trailer, but where. I ran the wires as suggested. It works the same as when I had it hooked up to the pickup. I have both turn signals when the headlights are off. Connect the headlights and all I get is the three lights strip at the back of the trailer, no taillights or side markers and the turn signals won't light when the headlight (brown wire) is connected.

[Blue Kayak]

At this point it might be quicker to just get a complete light kit and reinstall everything new. The next time I have to do this I'm going to make a light bar where the lights are placed on a 2" X 4" that is about 6 inches longer than the transom width. The lights on the 2X4 have a connector and there is a connector at the back of the trailer. That way you can take off the lights before you back the trailer into the water, and the light bar can be used on different trailers. Use bungee cords to attach the light bar to the boat and trailer.

[Phred52]

Cicada, So, Now you know the problem lies on the trailer, not the tow vehicle. Did you remove, clean and reinstall the (-) grounds? That would be the next item to look at. From there, I'd get INTO the tail light assemblies themselves. If they're the sealed type, replace them, if not, with no voltage connected to the trailer, pull out the bulbs, look at the inside of the sockets (for corrosion) clean it out thoroughly, clean off or replace the light bulb itself, I like to lube the bulb base with dielectric grease,(conducts electrical flow and delays the corrosion from reforming), reassemble. If I'm reading what you're saying correctly, You don't have a big show of sparks when you hook up lights, correct? That tells me your wires are not shorting to the frame. I'm leaning toward the bad ground on the frame making the circuit seek a ground by feeding back through the tail light circuit to get to a good ground. OR.... You can do as the post above states and replace the whole system. Good Luck, Let us know, Phred52

[marine_man]

I agree that it's definitely in the trailer, and yes, it sounds like you have a good ground on the vehicle side.

Based on what you're seeing I sure think you have a grounding issue...

Did you remove, clean and reinstall the (-) grounds?

This is a great place to start... do this at the pigtail ground on the trailer side (the white wire coming off the pigtail connector - is it screwed to the trailer or connected to a bolt?)

Also, with respect to the brake lights - one way to check all light function is to turn the tail lights on and turn your hazard lights on - if the tow vehicle is good and all your lights work correctly you've just tested your turn signals, brake lights and tail lights all at the same time.

marine_man

[Phred52]

Good point MM! I'm not real familiar with the newer vehicles wiring, but on the older tow vehicles, the Left turn signal also controlled the trailer's brake lights. Cicada, checking that pigtail is a real good place to start. The only thing I'd add is if this trailers tongue is bolted(not welded) on OR if the trailer tilts, clean that joint up REAL good and run a permanant jumper wire from the tongue to the rail of the frame. This spot is often overlooked as the ground problem area. Phred52

[Cicada]

Ok, imagine a 300 lb plus guy doing a dance in his yard that looked like a cross betweeen the Micheal Jackson grab you boy stuff jig, a Snoopy nose in the air on your tippy toes slide, and a John Travolta in my leisure suit disco dance. That's me!

I think the group home next door is cleaning out a room for me!!

Something deep in the gray matter between my ears decided that the two ground wires by each taillight should be tied together, but not attatched to a bolt on the trailer. I assumed (you know what they say about assuming)that if the ground wire on the pigtail was working correctly (and it was), the rest of the ground wires just needed to be connected together. The whole thing lit up like a Christmas tree.

Thank you very much to everyone that had suggestions and were polite enough to not just say, (use your Patrick Reuse voice), "Check the ground, you moron." I really appreciate the help you can get on this site.

Now there are four lakes that need my attention at the end of this week.

Hey marine_man, did you know Valerie that used to have a beauty shop in Lisbon? She was a high school classmate of my brothers in Cooperstown.

Oh, lookie there, the venison roast in the crock pot is smiling at me. Time to go.

Thanks again,

Greg

[Phred52]

Glad to hear you got it resolved. Was connecting them together a recent activity?? Go give those lakes the attention they deserve!! BTW... I know EXACTLY what dance you're refering to!! Phred52

[marine_man]

Sorry... I'm a recent implant to lisbon... grew up in the St Cloud area..

Glad to hear you got it figured out!

marine_man

[Cicada]

The logic in my gray matter thought that if the ground wire worked at the hitch, they should be connected together. More than likely, I did not find them that way and the original problem was the ground at the rear, not the lights.

Still dancing.