There's yer problem



A mirror is very useful for boat and trailer maintenance



LED Trailer Lights

The running lights on the trailer have been misbehaving lately.   On the way back home from the WaterTribe NC Challenge the fuse for our car's running lights (and the trailer's) blew out.   The problem had to be in the trailer because the fuse blew out only when the trailer was hooked up.  Finding it could take forever.  Or not. 

Well  there's  yer  problem!  

With a lamp and mirror in hand,  it didn't take long to find an obvious problem.... 

The problem...      Yikes!

The wire serving the port fender's running light had been smashed flat by a washer a few months ago when I was repairing a bent fender.  Oops.  While very sad for that poor gruesomely mangled wire,  the problem was identified and now all but solved by an easy repair.  Eureka!  



That's better...  sort of.

The first step was to free the wire.  An autopsy revealed that the copper strands in the wire were flattened but not broken.  However, the edge of the washer had put a nick in the wire's insulation and a hole had formed.  The result was a short circuit and some blackening/corrosion of the flattened strands of wire.

The hole in the insulation of the flattened wire

The repair was simple:  I cut out the flattened section of wire, rejoined the cut ends of the wire,  wrapped the splice with electrical tape, and sealed it with a few coats of "liquid electrical tape" (3M Scotchkote Electrical Coating).  The only thing left to do was to give it a test. 

It worked.  All the lights were bright and the fuse in the car did not blow out.  Success.

The port-side fender's running light served by the flattened wire:  Taa Daaaa!

But wait, that's not all you get...

No so fast:  one light on the trailer was not lit.  The starboard fender's running light was not working.  Perhaps the LEDs were burned out?  It turned out that the problem was corrosion on the brass contact coming out of the back of the sealed unit.

Corrosion on the brass contact in the upper right corner of the unit

Corrosion reduced electrical contact between the sealed unit and the aluminum frame

The repair:  clean off corrosion and apply dielectric grease to prevent/reduce future corrosion.

Success

Not done yet...

Now that the starboard fender's running light was working properly,  we're done.  Right?

Surprise!  The port fender's running light was no longer working.   It seems the non-working light also had that same corrosion problem but the corroded electrical contact was still adequate  --as long as the light on the opposite side was out and not drawing current.   Again, cleaning off the corrosion and applying dielectric grease solved this last problem.



Good for a while

What are the chances the trailer's wiring and lights will remain problem free forever?   I'd guess "zero" if we continue to go sailing.   LEDs will fail,  contacts will corrode,  wires will become damaged,  etc.   But we're good for a while and now we know how to make incredibly flat wire.