CallMeVilla

Have two lights on brick pedestals that stopped working. Current comes from low volt transformer that also feeds to landscaping lights. The landscaping lights work.

The pedestal lights do not light ... I rechecked the wiring and it is correct and tight ... but while testing the current with a clamp meter, I noticed the bulbs are warm. HUH?

Ideas guys??

Wuzzat?

They have somehow gotten themselves in series, rather than in parallel.
This should be interesting.

CallMeVilla

Weird thing is nothing changed .... They were working then they were not. Nobody messed with wiring or dug in the flower beds ...

I wonder if the landscape guy did something while everyone was gone??? Hmmmmm??

kok328

using a volt meter, check the primary and secondary voltage at the transformer and this will let you know which direction you will need to start troubleshooting. If wired in series, the problem will be before or at the first lamp not working.

Wuzzat?

If the bulbs are warm but not bright there is a warm, high resistance, bad, connection somewhere.
In this context, high resistance may mean anything over 0.05 ohms.

CallMeVilla

OK, Sparkies, here is some more info ... The happy homeowner replaced the old pedestal fixtures with new ones (4 incandescent bulbs each, candelabra size). Clamp meter measure 12.2v at the first fixture and I got continuity inside the bulb socket. With just ONE bulb in the socket for each pedestal, NO LIGHT.

The wire is 12g and the run is only 25 feet, so there is no issue with voltage drop.

SUMMARY: I have power to the socket (12v DC), new bulbs, no light.

I am stumped ... Ideas??

Wuzzat?

Socket center contact spring is not touching bulb base center contact because it's bent down and has lost its spring temper?

I carry a little hook in my toolbag made from a coat hanger wire to pull up these bent contacts.
The bulbs may have been warm due to heat dissipated in the high contact resistance due to low contact pressure between the weak center spring and the bulb.
You could test this idea by temporarily wiring another socket/bulb combo across the socket that does not light the bulb.

If what's happening does not seem possible it means you are assuming something that is not true and figuring out this 'something' can be pretty difficult.

nealtw

120 volt bulbs, in a 12 volt system?

CallMeVilla

VICTORY. All the smart guys here .... Neal got it right ... The "Happy Homeowner" installed the new fixtures properly but used 120VAC bulbs but the power was 12VDC. Just enough to heat the bulbs but not light them.

I replaced the bulbs with 12VDC 15W clear bulbs and BINGO . . . we solved the problem.
After all that advanced testing, clamp metering, transformer testing and technician discussing ... it was a simple as mis-matched bulbs.

NEAL GETS A "LIKE."

nealtw

Evan when it's your own work that dosn't work stand back and look for the stupid stuff. Bin there done that.