LED keeps blowing in Proto 2000 GP9

I have severall Proto 2000 GP9s and GP7s which I have converted to LED lighting. But for reasons I cannot fathom one of the 2 LEDs keeps burning out. I use 2K ohm resisters which should be sufficent. Its always only the one led and not both. Is there something I am doing wrong or do I just have bad LEDs?

Dave

Maybe check to see that both sides of the one blowing all the time has resistance to it?

Bob

Are you DC or Dcc? Are you using “white leds”? White leds do not like “back EMF” This can occur if the engine is moving one direction and you throw the reverse switch while the engine is still moving. A reverse voltage spike “back EMF” will occur and blow the LED. Should not happen on Dcc.

The problem can be corrected by installing a diode in series with the Led. Any signal diode like a 1N914 or 1N4148 will do. A 1N4001 will also work but is a little larger.

Are you sure they are 2K resistors? 2K would make a very dim LED on DCC and one you’d lucky to get to come on without running full throttle on DC. 2K would be red-black-red.

–Randy

Thanks guys for your responses. Yes Bob, both LEDs have 2k resisters and Ned, your solution to put a a diode probably will work. I was unaware that the White LEDs were so fragile and suffer from back EMF. That would explain why none of my yellow LEDs never pop and Randy the LEDs are very bright with a 2k resister and I sometimes use higher. I have a great electrionic device called a Resistence Box that allows you to dial in any value from 1ohm to 100k ohms. Its a great tool and with it you can set your LEDs to any brightness you want and my layout is old fashioned DC.

Dave