LED Works in Some Fixtures, only Partial in Others

[FIRE UP]

Originally Posted by Milehghcty

Thanks all for the suggestions and help. I did get all of the little diodes on 68-smd LED bulbs to work today. It was caused by too much voltage drop as several suggested. The main light switch when you walk in the MH turns on 10 bulbs in 5 dual ceiling lights. if I go and manually turn off several (half) the lights, the LED will light as designed. If I plug in to shore power, I can have all the lights on and the LED will still light. Haven't taken a voltmeter reading yet, but must be real low when off shore power (strange as my interstate batteries are only a year old). So I'm thinking if I change all the bulbs to LED, I should be able to run most the fixtures at he same time. On my next LED purchase, I need to buy lower voltage bulbs. Thanks again.

As far as I know, you cannot buy "Lower voltage" LED bulbs. LEDs operate in a range of voltage. Usually not lower than around 8-9 volts and, not higher than around 14 or 15 volts. But, all of them require a resistor anyways to drop them down to around 2.5-3 volts anyways.

Try to supply an LED that is not resistor equipped with a full 12VDC and watch what happens, POOF!
Scott