Bad joke or coincidence? wiring question

So I got an odd situation going on here with my trailer. Every time I take the boat out I make sure the trailer lights are working. Last time I took the boat out the trailer lights worked perfectly normal. By the time I got to my buddies house they all stopped working. Tonight I check all the fuses, grounds, etc and everything looked good but the lights still don’t work. So I take apart one of the lights and both bulbs are burnt out. Thought to myself its just a coincidence, after taking all the housings apart every single bulb was burnt out.

For some reason I don’t think its a coincidence. What would cause every bulb to just go out like that? They didn’t get wet and I went through the exact routine I do every time. Thanks

It’s odd the bulbs are going before the fuse. Last two trailers I had issues with rather than repair I just gutted and replaced every thing. In a hour or two and $50 or $80 for LED you can have it done better than most factory wired trailers. Thow away all the crimp connectors and solder and shrink tube all connections.Grommet any place you go thru the frame and fasten all of it tight to the frame. My last Shorelander I had to fool with the wiring since it was new. They had a harness that all plugged together in about ten places.Can’t guess how much time I spent messing with it before I thru it all away and did it right. Make sure to hook up the ground wire all thru the system. Sounds simple but amazing how many people count on the ground thru the ball. If your trailer is bolted rather than welded it may help to run your grounds all the way to the lights. One more thought. If you bought a pack of bulbs that were not a brand name go to a parts store and try a major brand name like everything else they come in different qualities.

A short somewhere in the system? I had a similar problem years ago. Long story short,I found out totally by accident I had two fuse boxes on my truck (2000 Chevy) and had a blown fuse. In the end, I found the cause. I had backed my trailer into a log busting the lens off. Figuring I had the answer to my problem I replaced the lens and bulb but sill had light problems. Turns out the bulb holder itself was slightly bent causing a short when I applied the brakes. Replaced the whole light and no problems.
You may have some issues inside your trailer light plug (the one you plug into your tow vehicle)too. Take it apart and inspect it for corrosion,loose wires. I do that once a year and clean/grease the connections = easy.
Dunno, pretty much an idiot here when it comes to electrical systems so I cold be way off base. LOL

Sounds like you had a short to me. Its a little odd that no fuses blew in the process though. I would just replace one set of lights and then hit your brakes and blinker to see if they burn out again. Are you over fused anywhere?

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Are you over fused anywhere?

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or a bad ground. I had that on a shorelander trailer years ago. The ground wire was loose in the harness and would arc. Ohm meter and check each wire.

This is a strange one.

It’s not a “short”. If there was a short in the trailer wiring it would blow a fuse in the truck, not the bulbs.

It’s not a “bad ground”. If the “ground” was bad, no power would flow through the circuits and none of the bulbs would light up.

I only know of two ways to blow up an incandescent bulb. Either light it up when it’s under water, or give it too much voltage. There’s only the 12 volts in your truck so I have to wonder if you might have had them wet and not realized it?

I tell you what, I’m a trained electronics technician, a Ham Radio operator…and if this happened to me I’d be standing there looking at it and saying “What the heck????” (or something similar).

By the way, the advice to pull a dedicated ground wire through the trailer is one of the best things you can do to reduce trailer light problems. If you use a solid run of wire for “ground” it will eliminate a lot of intermittent flakey problems.

Rootski

Exactly Root!

..and to have them all go out. Running lights too??

If it’s just the tail lights/turn/brake I would bet a quarter they were wet. If ALL the lights went out…something smells fishy so to speak.

I’m not an electrician and I don’t play one on the internet, however I was a cb radio operator in the ’70’s.

Just wondering, if it’s only the back two lights, check for cracked lenses or the condition of the whole light housing.

I never disconnected my trailer lights for over 11 years. Then one day my left light kept buring out after every trip. Through the guys here on IDO I found these lights are made to trap air in them, thus keeping the water away from the bulb it’s self.

At some point the lens was hit by something and allowed water in.

Quick fix? Replaced it with an led bulb.

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Quick fix? Replaced it with an led bulb.

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BK where did you pick up those replacement bulbs, and what did they cost? Thanks!

Two for about $16.00, but remember it’s much less expensive the finding a Shorelander light fixture!

Oh Oh O’Reilly’s Auto Parts.

I’m not an expert either but i’d put my money on an insuffiecent ground/corroded wire inside casing, etc. causing it to draw higher amps. Or like you said a prank, lot of work for a prank though.
I also do the same when I rewire, run a dedicated ground to each light because grounds seem to be 90% of most problems.

I would go back to the fuse or fuses, just because a fuse looks good dont mean it is. Take an ohm meter to the fuse to check continuity, sometimes shaking the fuse a bit while checking with meter will tell you if the element on fuse is sometimes working or not. In my line of work I have run across this before.

Not sure why all bulbs are burnt out though.

Wow, I really appreciate all the responses and help from everyone. I ended up just replacing all the bulbs and re did all the grounds. Took the truck and boat around the block a few times and everything seems fine. I still wish I knew EXACTLY what happened. Thanks everyone

Trailer Wiring

That should be pegged to the top of the trailer forum.