LL P2k GP38-2 decoder concerns

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DakotaLove39

DakotaLove39

Always Improvising
Hey all.

If no one has noticed, after racking up a grand 61 posts, I went on a major hiatus, being drawn more to Warhammer 40k and airsoft for that time.

So, after gawking at my $50 BNSF 2099 in my room, I decided "What the hey. I can work this into my time."

I've been poking my late interest into DCC and decoders, since my crown jewel is DCC capable. However, today I found a website listing a wiring concern with Lifelike's Proto2000 GP38-2's.

http://www.tonystrains.com/technews/loconews/life-p2k-wiring.htm

According to the article, there are some factory problems with the wiring through the number boards, which could cause some big problems with the decoder.

The only problem is that there doesn't seem to be any date on the article, nor any kind of reference as to whether or not LL has fixed this. Can anyone tell me if my particular model suffers from this same defect, or has it skipped the beat? I can't find any date of manufacture on the documents included with the engine.
 
Does the box say it's made by Life-Like or Walthers? If it says Life-Like, you've got the problem described at Tony's.
 
Yeah it's the Lifelike one. I'm gonna take it in to work and if we're dead like last night, I'll see if I can re-work the wiring. If not, I'll just sever the number board lights and attend to them later.
 


I don't think the problem was corrected. I've got 3 GP38-2s and just pulled the number board lights from all of them. You can still see the number boards somewhat, but it doesn't bother me, since many of my other locomotives (Atlas and Athearn) you can't see their number boards lit up either.
 
I don't know how the plug and play board is connected, but couldn't you just bypass the board entirely? I assume that the number board lights must be connected to the board via wires and not PCB traces (please correct me if I am wrong, but that would be hard to do). I would just cut the wires before they get to the PCB and then manually splice them into the decoder before it goes into the board. That should take care if the problem if the problem is not on the PCB itself. It is not that difficult.
 
ICG/SOU said:
I don't think the problem was corrected. I've got 3 GP38-2s and just pulled the number board lights from all of them. You can still see the number boards somewhat, but it doesn't bother me, since many of my other locomotives (Atlas and Athearn) you can't see their number boards lit up either.
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X8. I did the same fix to all of mine.

Edit: FWIW, the P2K GP/SD60's have the same problem.
 
Unfortunately I didn't get a chance to actually do any wire work while I had the thing dissassembled. Our retail store was still on the dead-slow side, but I had a few housekeeping chores to attend to.

The only concern I have at this point with re-wiring is that I wouldn't know which wires are the track wires. There are atleast two pairs of black and red wires poking up from the trucks, and I can't find enough of them to see where they go exactly.

So shortly tonight I'm just going to snip both number board lights out and put them aside. After this, I'll have to decide which decoder to get and install. Any suggestions?
 
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The Digitrax DH123D is a basic drop in decoder and goes for about $15. That is, unless you want sound...:)
 
UP2CSX said:
The Digitrax DH123D is a basic drop in decoder and goes for about $15. That is, unless you want sound...:)
Click to expand...

I'm really too new to DCC to care. Just looking to get a decoder and a Digitrax controller, so I'll have a reason to upgrade away from my old Powerloc track.

Now this is actually kinda confusing here. It looks like maybe the problem has been fixed, as the plug covering the DCC pins is what the number board lights are wired into. So.. without that plug there that means the number board ligh circuit is also removed. However, It could just be me having a n00b moment, as everything else is wired into the same little plug.***

My real question here is, is it the bulbs themselves that screws up the decoder, or is it the entire circuit powering those bulbs?


***Noob moment. I got help from a diagram using the P2k SD60. I see how it's done.
 
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The P2K series locos I have use a DH163/165L0 decoder. All the wires from the motor, the track/trucks, and lights go into that 8 pin NMRA plug on top, into the analog "board" on bottom. The easiest swap is to go with a DH165L0 decoder, and follow the instructions in the package. Be sure and keep that Kapton tape (looks like old Scotch tape), because that tape will insulate the decoder from the frame weights.

The problem with the number board lights on the GP38-2 and GP/SD60 series is that P2K wired the lights to the track leads, as they need 12v to run. That's why splicing them in with the directional headlights won't work. It's easier to pull them loose completely, especially if you are about as electrically inclined as I am.
 
So the problem itself is because of those lights drawing power straight from the track and not through the motor? If that's so, I can see how the decoder would be fried.
 
Yes, that's the problem with those runs of P2K engines. The light board itself is powered from the trucks so it makes the motor grounded and fries the decoder. Not all the models of the GP38-2's and GP/SD60 series had this problem but I don't know when it was corrected. You can always use a meter to check for continuity with the light board and motor. If there's continuity, you need to replace the numberboard lights or just remove them and cut the wires.
 
Don't be scared of rewiring. With DCC, there is a standard color code. Here is the sight.

http://www.nmra.org/standards/DCC/standards_rps/DCCStds.html

The black and red wires are the power pickups. The red wire should be the engineers side and the black one the fireman's side. Orange and Grey wires go to the motor. Blue is the common wire for accessories. All other colors operate certain accessories. Form the description of the problem (if I understand correctly), I would solder one side of the board lamps directly to the blue common and the other to one of the other accessory lines. I would also suggest hooking them to the function output line directly and NOT PLUGING that line into the board. This should effectively bypass the board and eliminate the problem. It sounds scarier than it really is. Just remember to use heat shrink to stop possible shorts and pliers and/or a good soldering station is a major help.
 
dpeterson3 said:
Don't be scared of rewiring. With DCC, there is a standard color code. Here is the sight.

http://www.nmra.org/standards/DCC/standards_rps/DCCStds.html

The black and red wires are the power pickups. The red wire should be the engineers side and the black one the fireman's side. Orange and Grey wires go to the motor. Blue is the common wire for accessories. All other colors operate certain accessories. Form the description of the problem (if I understand correctly), I would solder one side of the board lamps directly to the blue common and the other to one of the other accessory lines. I would also suggest hooking them to the function output line directly and NOT PLUGING that line into the board. This should effectively bypass the board and eliminate the problem. It sounds scarier than it really is. Just remember to use heat shrink to stop possible shorts and pliers and/or a good soldering station is a major help.
Click to expand...

I'm just wondering, did you read the posts above yours? Because they seem to state that the fact that the lights bypass the board is the entire problem.
 
I think I must be misunderstanding then. I did read the posts above. I though they meant everything was soldered to the PCB and then a PCB trace in the wrong place caused the lights to short one of the functions directly to the track. The lights are attacked to the track power via wire and to the board then? I wish they put out a schematic of the problem.
 
So now here's my other question. On the Digitrax website it shows a completely different decoder from the one I was directed to get here. The one listed for me in this thread looks like a concentrated bundle, all neatly wrapped up, whereas Digitrax shows one the same size and shape as the current circuit board sitting on the back of the locomotive's weight block.
 
DakotaLove39 said:
So now here's my other question. On the Digitrax website it shows a completely different decoder from the one I was directed to get here. The one listed for me in this thread looks like a concentrated bundle, all neatly wrapped up, whereas Digitrax shows one the same size and shape as the current circuit board sitting on the back of the locomotive's weight block.
Click to expand...

The decoder isn't significant. The problem is in the loco wiring.
 


I'm not sure which two decoders you're talking about but Digitrax decoders usually have blue plastic covering the circuit board and NEC decoders have just the bare circuit board. It's a good idea to wrap any bare circuit board in Kapton tape before putting it inside the shell to prevent any accidental short circuits. Other than the wrapping, both lines of decoders are functionally the same for the amount of functions they have.
 
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