I have some 12v AC halogen downlighters in my kitchen, wired in pairs to a connector box and then a transformer. I replaced one pair of the lamps as the casings were damaged, plus they were playing up - not coming on straightaway and so on.
The new lamps are suffering from the same problem. When I switch the power on neither come on, but if I remove one of the plugs from the connector box, the remaining light comes on. This works for either lamp. Sometimes they will both come on after a period of time, but if I switch the power off and on again, they stay off.
Can anyone explain what the hell's going on? Is the the transformer or the connector box?

Kevin, April 2006

is there any danger if you connect two 50w lamps on a single 12v transformer?

Gesis, May 2014

Have 3 halogen downlights in kitchen. They all come on together, but after a time, one goes out. It then comes on again after a few minutes. It worked fine for 7 years, but now this has started to happen.

Also, if it is a bulb problem, how do I get the old one out?

Kiwi - Nan, December 2010

I have a set of halogen downlighters, some of which are not working. Changing the bulb does not help, as new bulbs do not work wither. My electrician replaced a 'transponder'???? last time - any one know what this is - what it looks like & how to buy & fit it?

JeniFER WRIGHT, October 2010

I found the same problem with a set of lights I purchased for my kitchen. The set came with 6 lights and a 60 watt transformer. It also came with 20 watt bulbs in each of the lights! 120 watts of lights through a 60 watt transformer blew out the transformer. I decided to just split the system in half and run it off two transformers instead.

The moral, don't trust these light sets as they come packaged. Check the light wattage vs. the transformer wattage to save yourself a headache.

fzurmk, June 2006

Most of the DIY transofrmers are 50watt...this is great as so are most of the DIY downlights that run off them...SINGLY. If you decide to run two lights off the one transformer, you need to be sure that it is either a 100watt transformer or that you get hold of 25watt lamps (they will fit the 50watt socket with no problem, so sometimes it is tricky to tell).

If you try removing one of the bulbs and the other always comes on reliably, and then you swap them and the one that was missing now comes on reliably while the first one is out then it is definately a transformer that just can't put out the power to fire up both lights. It will work "sometimes" because many tranformers kick in with a power spike and if it is enough to get the lamp started then it will keep glowing, though somewhat dimmer then it should. Sometimes it just sits there for several minutes and suddenly gets the power spike or just a sufficient buildup to start...it is howvere killing your tranformer.
Get a bigger one or go down to using 25watt lamps.

Alex

Alex, May 2006

Sounds like your transformer doesn't have the power to turn on all your lights, try removing one light and switching the power on again

Darren, April 2006