On 12/5/2016 9:03 AM, DerbyDad03 wrote:
I've been looking at buying some LED Christmas lights but I'm curious about
the wiring harnesses.

I know the bulbs are brighter, last longer, etc. However, I'm curious as to
whether the wiring harnesses are any different/better than traditional
mini-light strings. Do LED's strings go bad in sections just like
traditional strings or are they wired such that each individual socket is
a stand alone entity?

I have a large number of mini-light Christmas strings. Straight, icicles and
swags. Every January I put away full working sets and every December I plug
the strings in to find bad sections scattered throughout. I try all the
standard bulb tricks and sometimes I can get the sections working, but
sometimes I can't.

I'm not talking about entire strings being bad, I mean that one or more 4'
section in a 21' string will be out. Then I have to buy new strings or
combine strings by cutting out bad sections and soldering in good ones. It's
a constant PITA.

Replacing all my strings with LED's would be a huge up-front expense, but
if I knew that I could pull them out every year and they would work, it
would be worth it.

I've never had to cobble in new sections of lights because string are
bad. Yes, I've had an individual bad socket and usually can fix it.
Mostly it's bad lamps. Each lamp had a shunt in it to maintain the
circuit when the filament burns out. The shunt is supposed to burn
through and keep the circuit going. However, many times the 120VAC or
177 volts peak won't burn through the shunt and the string won't light.
Using one of the zapper guns (Lightkeeper) will usually "fix" the bad
shunts by putting a higher voltage pulse through the string, causing the
shunt on a bad bulb to burn through. However, multiple bad lamps and
corroded sockets usually can't be fixed this way. I built a test box
that allows me to probe down the string and find the bad bulb. This
works great especially where you can lay out the entire string. There
are resistors in the test box that prevent burning out the lamps if only
a small section lights while probing.

Many years ago I bought 3 skinny trees which were factory prelit. These
light strings don't have shunts ... thanks Menards! So the zap gun will
not work. So, it's probe from one lamp to the other. Because the wires
are wound so tightly around the branches, it's really tough to go down
the string, but with some patience they are still lighting. Seems no
one carries these lamps, however, I did find an Ace store in Indiana
where they had some. I had them ship me their entire stock, about 10 or
15 cards of 5 lamps and until they are used up, I'm good.