Large Scale Central

Accucraft K-27 head/marker lights fail

Problem Solving
#1

I have a recently aquired 2nd hand electric Accucraft K-27, it has Sierra Soundtraxx card fitted. I accidently pulled off the smoke box front the other day. When I replaced it the head and marker lights no longer functioned in forward motion but the rear tender mounted light, only, still functions perfectly when the track current is reversed. I checked the wiring on the small circuit board, looks like Accucraft’s standard 6v voltage regulator assy’, mounted in the smoke box and the only thing amiss was one of the legs on a tall cylindrical object (sorry I have virtualy zero understanding of these things other than simple wiring) on the board had come adrift. I soldered this detached leg back into what appeared to be the correct position on the board. But still no front head/marker light function but reversing light ok. All the wiring to the head and marker lights seems ok with no apparent breaks. Any ideas on what is going on here and what I might need to do to fix ?

I’ve had some good technical advice on a UK forum I have posted this on but I thought there may be more of you familiar with this loco and experienced this problem here and know a simple solution. It’s the odd fact that the reverse light works ok but the head and markers don’t that has me scratching my head. Your input and ideas would be greatly appreciated.

#2

Max;

Those are NOT “Marker Lights” on the front end.

They are “Class Lights”, or Classification lights. Green to indicate a second section following, or White, to indicate an extra train, not on the employees’ timetable.

“Marker Lights” are on the caboose, bringing up the rear. (Of the train)

During daylight hours, flags of the appropriate colours replace the lights.

I send this note to you, just to enhance your knowledge of the lights and their purpose, on your locomotive, in case you are interested.

Fred Mills

#3

I think I’m already helping you on the other forum. Just take that multimeter, set for DC and start measuring…

Greg

#4

Greg Elmassian said:

I think I’m already helping you on the other forum. Just take that multimeter, set for DC and start measuring…Greg

You are and it shall be done, was just wondering if anybody had direct experience of the same issue over here. Not so many electric Accy K-27’s in the UK. Multi-meter at the ready, set for volts first, I think I’ve now worked out the process needed for validating the stuff on the PCB, thanks again for the diagrams. All is clear in my head now. Ohms for later as I still want to chase down a possible short issue, I’m going to pull out the bulbs and wiring for the head/validation lights anyway as there seem to be some future risks the way it’s installed right now.

#5

Actually I have a couple of Accucraft steamers with the 6v regulator, and on mine, the regulator IC was hidden underneath the motor screwed to part of the chassis… it looked like the wire just ducked under the motor and for the life of me could not figure out where the 6v came from.

Greg