Trailer lights?

[tommyk]

This one is new to me. All of the lights on my boat trailer come on with the vehicle lights like they should, but the turn signal and brake functions do not work on either side. I have only had light/wiring completely out of commision, never partial like this. Oh, and I have checked the wiring coming from the truck and I get L/R turn and brake functioning properly on my test plug.

[BobT]

One possibility - I'd be looking at what is incorrectly referred to as ground circuit. All too often I see trailer hookups that rely on the toungue and ball to serve as the common (-dc) for the circuit. There should be a wire designated for this connection. The ball and toungue is not reliable.

Bob

[Kyle Sandberg]

Under the hood there should be fuse box that contains the fuses that function all the towing lights. Check those to see if they've blown. Sounds like the case to me.

[glendam]

Are the bulbs blown?

[Jeremy airjer W]

Sounds like he is getting power on the truck side K dawg.

Have you checked to see if the bulbs are burnt out. The brake light and turn signals share the same wires. Its unusuall that both would go out at the same time. If it where a ground issue I would expect some quirky like all lights blink when turning left and no lights when stepping on the brake, which is not the case.

Like I said check the bulbs. While you have the cover off check for power at the bulb socket. There should be continuous power on one of the wires (with the tail lights on) and either blinking power or continuous power (whether or not you have the brakes on or the four way flasher) on the other one. If there is no power than there is an open circuit between the plug in and the socket.

[tommyk]

Thanks for all of the input. Yes, I am getting power from the truck. I will have to check at the light socket like you said Airjer. I for sure am getting the continous power flow since the lights do turn on and stay on, just not the blinking/brake power. I will have to wait until after work to actually take apart the tail lights. Now, I am assuming that as mentioned, I will not be picking up a indication of the blinker/brake power. So, since this problem is the same in both tail lights and happened at the same time, I am more than likely not looking for a problem with a bulb or even the wiring at the location of the tailights,or am I? Is it probably something with the wires further up in the trailer. I hope not because the trailer is tube frame and the wires all run inside of the frame.

[Shack]

Check bulbs!

But first, what kind of truck and how old of trailer do you have?

[Shack]

I have seen it many times, where a customer would come into shop and say there running lights are not working. Come to find they have been driving around with one for ever and the other on just burnt out.

Just an obsy.

[tommyk]

2001 Chevy S-10 Blazer and 2006 Yacht Club trailer. Did not get a chance to look at the lights/wires tonight, may have to wait until Wednesday. Keep the ideas coming!

[Cheers]

My 2003 Ford has 2 fuses,one under the dash and 1 under the hood,I had same problem . Lights worked , but didn't ! Fuse wasn't burned out ! Went to ford garage to get wiring fixed and they changed the other fuse! Daa !

Pays to read the owner manual instead of assuming.

[bucketmouth64]

I had the same thing happen like Cheers. Check all fuses. I didn't know about the second one. And if you have old lights switch to LED's. Best lights I've had.

[Shack]

You might have LED bulbs in trailer.

I would check the fuse box under hood! Run down with test light or look at with flash light. Or read owners manual.

[HaywardBound]

Quote:

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and I get L/R turn and brake functioning properly on my test plug.

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For that reason, I don't think it is a fuse.

Check for corrosion in the plugs. I use my Dremel tool with a small wire brush on the male part, and a smaller bit on the female end to clean up the connections. They look like new when I'm done.

Also, follow your ground wire up to your truck and make sure it is attached well.

[tommyk]

Well, everything is up and running! Checked all fuses that had anything to do with trailer, all were good as I suspected. Took apart both tail lights, no burnt out bulbs but noticed one fixture had quite a bit of corrosion started on metal components inside the plastic "submersible" bubble. In the process of taking apart the other light the running light function decided to go. Now I had one side that didn't work at all and the other no brake/turn. Bought new LED tailights and hooked them up. The brake and turn worked on both new lights, but still had running light out on one side. The problem with that ended up being a little further up in the wiring were there was a plug leading to this last light. The connection port for the brown running light wire was corroded and casuing a poor to no connection. Cleaned and sealed that and now I have all lights working like they are supposed to. So, turn/brake problem seemed to be in the lights since as soon as I hooked the new ones up, without any adjustments to the wires, the turn and brake worked on both. I didn't look into it any further to find exactly where on the lights was the problem. I was just happy that I didn't have to strip out and run new wires or no longer have to worry about anyone running in the back of my boat when I go out Saturday morning.

[tommyk]

I guess I am still not sure why both lights had the same problem at the same time if it wasn't the wiring?

[Jeremy airjer W]

Quote:

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I guess I am still not sure why both lights had the same problem at the same time if it wasn't the wiring?

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The important thing is they are working now!!

You went from regular bulbs and replaced them with LED's right? LED's require much less power to operate. You may not have solved the problem only masked it. If a wire/wires/conection still has a corrosion/connection issue it may not show up again until it gets so bad it can not supply enough power to the LED lights. Just a theory!

I think I would have made sure I knew why the old ones didn't work before replacing with new. Just for my own piece of mind.