we have 4 halogen spotlights in our bathroom cieling (been there for ages with no problems) but now every time we try to switch light on the power trips to the whole upstairs lights but no bulbs have blown in the bathroom. we did have a dimmer switch and thought it might be that so changed it to standard switch but still the same problem

jane, September 2007

If the circuit breaker trips immediately when you switch on the lights then you have a short in
a. the wires between the switch and the fixtures
b. one of the fixtures or
c. one of the lamps (lightbulbs)

c. is the easiest to test, so do that first -- remove all the lamps and see if the switch still trips the breaker.

If it's not that, then you'll have to start checking deeper; separate some of the fixtures from the others to narrow down where the problem could be, etc. I once saw a house where mice had eaten all the plastic insulation off the electric wires in the attic, leaving the copper conductors free to touch and short out.

ChrisV, October 2007

have you checked the wiring above the light (with the power off) to make sure heat from the lamps have not damaged any cables and is there a transformer supplying the lights i.e. low voltage lighting.

Jason, October 2007