Lifelike Products Inc make a number of HO-scale (1:87) models of the EMD GP38-2 (Geep Diesel Electric Road Switcher Locomotive). This article is my attempt to write about installing DCC on these locomotives – it isn’t a particularly simple task.
DISCLAIMER: This modification is hard. You can damage your newÂ model VERY EASILY with the tools needed to perform the modification. TheseÂ instructions are designed to make the process easier, and are based upon theÂ successful modification of no less than eight Proto 2000 GP38-2 models.
HoweverÂ we can accept no liability for what happens to your model, nor do we guaranteeÂ that this modification will work. If you undertake the modificationÂ detailed here, you do so entirely at your own risk.
Remove it from it’s box – collect up the detail parts that haveÂ fallen off in shipping. Remove the two support brackets that holdÂ it in place for shipping.
As ever with a DCC install, always check the loco runs correctly onÂ DC before even starting the install.
Remove the body – despite confusing instructions in the manual aboutÂ them being secured by the brass screws when they’re all painted blackÂ (I don’t know about you but I’m really not that good at telling a blackÂ painted brass screw from a black painted steel screw by just it’s head.Â A masterly piece of useless documentation from the people at Lifelike.)
The screws you want are the ones hidden under the trucks (bogies) asÂ illustrated here:
After that it should prove reasonably straightforward to just removeÂ the shell of the loco.
You’ll be left with the Chassis looking like this. The tidy look andÂ apparently open connector belies just how much work lies ahead to getÂ this thing to actually work right with DCC.
Removing The Wires
After bad experiences with a melted roof, I’d say you have two choices at thisÂ point – replace all four bulbs with LEDs, or use a DCC decoder with a lowÂ current/low voltage output such as the Digitrax DH165L0 (or the previous non-RoHS DH163L0 if you find one on a dealers shelf) or TCS A6X decoders.
After my bad experiences with a Lenz LE1035 (due to the appalling vaguenessÂ of the Proto 2000 manual leading me to fitting the wrong type of replacementÂ bulbs), I found the DH163L0 decoder intended specifically for this breedÂ of Proto 2000 unit. Unfortunately this only caters for the headlights usingÂ the factory fitted bulbs; works fine on the Proto 2000 USRA 0-8-0 andÂ probably GP30 etc, the four bulbs of the GP38-2 model present a problem.
The headlights are catered for, but the two number board lights are not;Â I replace them with LEDs since the bluer colour is much less of a problemÂ when shone through the numberboards.
Since I did the first batch with DH163L0s, I’ve continued with this chip,Â although the more recently released TCS A6X with it’s six balanced lowÂ voltage outputs would save any need to replace bulbs (but would be aÂ little bigger (awkward) and would require a completely socketless install).
If you pull off the push-on plastic caps, unscrew the main PCB from theÂ chassis, you’ll be left with it looking like this – the Digitrax DH163L0Â board is visible in front. At the right hand end of the Digitrax DH163L0Â decoder, you should be able to see five little holes in the DCC PCB. TheseÂ are the solder points for the additional functions. I’m pretty certainÂ (please check) that the centre one is the blue/+Common (function common) andÂ one of the points just next to it is the F1 output.
I then build a small wiring loom which consists of a wire that will runÂ in the channel under the PCB towards the front of the loco. There is aÂ reasonable cavity just under where the cab will be where the resistorsÂ for the number board LEDs can be placed. I therefore bring the function commonÂ forward to this location where I place a little package of two 1K 1/6thÂ watt resistors wired in parallel.
This gives 500 ohms which is aboutÂ right (I’m told) and using two smaller resistors in parallel createsÂ more surface area to disapate the heat generated. (Least that’s myÂ theory; remember, melted roof first time, I’m nervous about where theÂ heat goes!). One leg of the front number board LED is soldered to theÂ end of the resistor pack (but only after testing the basic install becauseÂ I’m no good at telling which pin is which on an LED – I prefer to offer itÂ up and see it shine before soldering it in!).
A return wire back under the DCC PCBÂ takes the low current feed back to the rear of the locomotive for theÂ rear number board LED.
The resistor package itself is then sealed in heat shrink. Once done it
looks like this:
At this point in the install, the light started failing me and IÂ completed the install on B&M #204 by artificial light and couldn’tÂ take any more photos worth sharing. I now have three more units toÂ do and will photograph the next stages of the process as I do those.
Here is a diagramme that tries to explain how the extra componentsÂ are added to make the LEDs work. Note that the best place for the resistorÂ package to fit is in a gap in the chassis in front of the DCC board nearÂ the cab (under the dynamic brake blister on the model). The extra wiringÂ loom carrying it left of the board is to indicate approximate lengths of theÂ needed cables, layout, etc.
Quick Summary: Basically you re-wire the 8-pin connector such thatÂ the normal pins are connected – pickups to power in, motor to theÂ two motor pins – F0-Front to the front headlight, F0-Rear to theÂ rear headlight. Do the usual safety tests on the programming track,Â set the address and check it runs.
Then offer up the LED, find whichÂ way round it glows and solder it to the resistor package or theÂ lead from it. Repeat for the other LED. Check on a programmingÂ track again to make sure there’s no new short circuit, and then
reassemble the loco. Note that the position of the light pipes isÂ such that one LED is on top, while the other is below the bulb.