Landscape Lighting 12v AC

Thread Starter


Joined Feb 26, 2011
Hello AAC Forum,

Thanks to ronv, tkao21203, Sensacell, Colin55, Wendy, ebeowulf17, Dodgydave and others,
whose name I have missed, with DC circuits in the past.

I think that's my problem today. Except the occasional home repair, little experience has been acquired with AC.

The system being constructed is a landscape lighting circuit and it is 12 volts AC not DC. Pretty sure I know the issue but would like to confirm theory and query about an aspect of the solution.

Have wired a harness for the system as shown in plan A.

But the two lights on the east side don't come on. Tried
known good lamps and check for voltage with DMM. Both negative.

I believe the layout that will work is this and am in the process of testing.

I believe that the tee to the east side in plan fouls the path to the east side.
I am not sure, but it is surmised that the pulsing (60 Hz) nature of AC
makes a tee split off not possible. Or that an AC circuit can only pulse
down one main spine and that creating a bifurcation interrupts the
60 Hz alternation.

If that is true there is only one fly in the ointment: the tee configuration
exits at three of the four lights. At the last light the connection is a continuation
of the two connector spines. But on the lights between spine and the last fixture the
tee connection to the fixtures exists.

Perhaps a tee with a short extension will work but a longer, major second spine will not.

So the questions are.
1. Will an AC circuit allow a tee split as shown in plan A?
2. If so why does the tee juncture to the fixtures work?


Allen Pitts, Dallas Texas


Joined Jun 22, 2012
Ac will work just as good as Dc, if there is no voltage at the lights, you need to trace back the wires, and check it with a load like a bulb at each junction.


Joined Nov 30, 2010
The only thing magical in this is your thinking. If the connections are good and the wire is good, AC will go where you tell it to, just like DC.

Thread Starter


Joined Feb 26, 2011
Hello dodgyDave,

Reconstructed according plan B and tested positive.

But the construction using plan A is a lot cleaner 'cause
the snake around the bottom stair is eliminated.

Will retest plan A and advise.

Getting late on Sunday so will be next week before can