I bought two DH123 D Digitrax decoders. Old PK 2000 BL 2's do not have a printed circuit board. They have 14 volts light bulbs in them now. Here is my game plain.
Isolate the motor from the frame, that is easy. Old BL 2's are made a lot like old BB engines.
Positive side of the decoder will hook to the truck towers, just like the old Blue Box Engines.
Negative side will be grounded to the chassis, they all ready have a negative chassis ground which is different than the Athearn Blue Boxes.
Any thing I might be missing?
Cuda Ken
I hate Rust
Ken
Thats it. Check the stall current first. Some of the older P2K motors sucked a lot of juice.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
Thanks for the answer Pete, like the newer Proto very low power draw.
Any other ideas?
Dave, the bulbs do not touch the shell, they set in front of the lights and a clear plastic thing carries the light to the head light.
Well the decoder is installed and with out a installation hitch yet. It looks like the motor was all ready isolated from the frame. To be safe, I added to strips of duct tape under the motor, and coated the brass strip that hold in the brush in with liquid electrical tape.
One thing I did think off doing after I isolated the motor was to test if it was isolated. I hooked a power tire to the chassis and then to the upper motor contact, it did not run. Hooked the chassic wire to wire on the bottom and it ran.
This BLI was on the RIP track for a year or so. I thought the motor was toast. Found there was a missing spring for one of the brushes, replaced it and installed the decoder. It starting to break in and is getting quite and hauls well.
Ken,
You are missing the point about the bulb location. The old DC engine got about 12VDC to the rails. With DCC, the lamp output may be about 14 volts. The bulbs run 'hotter' and the heat can soften the plastic(trust me on this). A friend added a decoder to a stock engine and melted the cab roof due to the higher heat generated. A nice 'golden glow' 3mm LED should fit into your BL2. Just put a 600-1000 ohm resistor in line with the LED and you are good to go. The lamp is good for maybe 600-900 hours, the LED life is measured in 25,000-30,000 hours of life! And it runs 'cooler'. Remember, LED's are diodes and they are polarity sensitive. If it does not light, swap the leads.....
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin