I just learned the hard way that I should test the decoders before installing them, even if the paperwork says there is a 1.5V pad, dont take it for granted. Just installed 2 A6X decoders into 2 Athearn Genesis SD70's. First one went in, motor drive worked flawlessly, hooked the lights in, and wham, blew out every one of em. Thought maybe I did something wrong, so we re-studied the instructions, and wired in the 2nd one. Motor worked fine, all the lights blew. I finially checked the votage and I was getting 12 volts to my 1.5v lights. I got the A6X specifially so I wouldnt have to worry about resistors.
I spoke with TCS and they said that there was a small batch of decoders that went out with a small short that makes the 1.5v pad pump out 12v. I am sending it back and they said they will have new ones sent to me asap. Maybe they will give me some bulbs since now I am out 12 of em.
I got my decoders from DCCroundhouse. make sure you check the voltage before you wire in any new ones.