Pool and Spa Forum: Pool and Spa Forum -> Concrete Pool Light - Won't

Working on an American(sold by Pentair) 12V, 300W wet niche light. Giammanco transformer provides voltage to the light. Origional call was no light. After replacing bulb, it came on until after I reinstalled it. I checked the resistance on the new bulb and it reads almost 0 ohms, just like the old bulb. I then went to the distributer and checked a new bulb off the shelf. got the sme reading. With the bulb out of the fixture I get 11.5volts on the socket. Bulb still won't light. I jumpered the socket, with my meter connected in parallel and the voltage goes to 0V as soon as I put the bulb in the circuit. Is there a protective circuit in the American Probucts light fixture the causes the voltage to go to 0 when a load, such as a bulb, is added to the circuit?