convert GP-40 Diesel to DCC

[trif]

I would like to convert my DC GP-40 to DCC operation.  Can I just purchase the printed circuit board from the parts list.  Also, do I have to change the motor to the one with the resistors attached or can I keep the origional motor.  All help welwome Thanks

[Rangerover1944]

Bachmann has made a couple of different GP40 models and some have the DCC quick plug and others don't. The first release of this model was a split frame DC only that didnt leave much room for a decoder. I installed an n scale decoder and it and it works fine.  They later released the GP40 in the Spectrum line with no DCC quick plug but you could get a decoder that replaced the circuit board on the top of the frame. This particular loco isn't split frame and they upgraded the circuit board on the top of the newer models and have a DCC quick plug.   Converting most engines to DCC is pretty simple with or with out the DCC quick plug. Hard wiring is not as difficult as it may seem to be, just do one and you'll find out how simple it is, if you follow the instructions that come with decoders that need hardwiring. Split frame engines take a little more thought and planning since a lot of the design of the engine's  are really simply grounded contact points built into the engine that need's to be isolated from the motor.  I've converted 3 loco's with split frames, it does take a bit longer, but it can be done.
hope this helps, Jim

[Donbey]

I have a Bachmann GP-40 and a 4-8-4 Norther.  They are new, but Analg can I use Bachman decoders with wires and not a pin and make them work.

[mf5117]

You can buy a Bachmann DCC GP-40 for around $45.00 US. And save yourself alot of work . But only if you want the experience ,then go for it . Have Fun

[EJELen]

Bachmann has made a couple of different GP40 models and some have the DCC quick plug and others don't. The first release of this model was a split frame DC only that didnt leave much room for a decoder. I installed an n scale decoder and it and it works fine.  They later released the GP40 in the Spectrum line with no DCC quick plug but you could get a decoder that replaced the circuit board on the top of the frame. This particular loco isn't split frame and they upgraded the circuit board on the top of the newer models and have a DCC quick plug.   Converting most engines to DCC is pretty simple with or with out the DCC quick plug. Hard wiring is not as difficult as it may seem to be, just do one and you'll find out how simple it is, if you follow the instructions that come with decoders that need hardwiring. Split frame engines take a little more thought and planning since a lot of the design of the engine's  are really simply grounded contact points built into the engine that need's to be isolated from the motor.  I've converted 3 loco's with split frames, it does take a bit longer, but it can be done.
hope this helps, Jim

[/quote]

Does this philosophy also apply to the SD40-2 Non DCC equipped locomotives? (Item 67003) I haven't taken it apart yet, but I assume that the motor still needs to be isolated from the frame. Can you use the NCE replacement for the DCC On Board  (NCE BACH-DSL) in the non DCC units?

Thanks for the link and the explanation. It really helps us novices.

Len S

[Rangerover1944]

Bachmann has made a couple of different GP40 models and some have the DCC quick plug and others don't. The first release of this model was a split frame DC only that didnt leave much room for a decoder. I installed an n scale decoder and it and it works fine.  They later released the GP40 in the Spectrum line with no DCC quick plug but you could get a decoder that replaced the circuit board on the top of the frame. This particular loco isn't split frame and they upgraded the circuit board on the top of the newer models and have a DCC quick plug.   Converting most engines to DCC is pretty simple with or with out the DCC quick plug. Hard wiring is not as difficult as it may seem to be, just do one and you'll find out how simple it is, if you follow the instructions that come with decoders that need hardwiring. Split frame engines take a little more thought and planning since a lot of the design of the engine's  are really simply grounded contact points built into the engine that need's to be isolated from the motor.  I've converted 3 loco's with split frames, it does take a bit longer, but it can be done.
hope this helps, Jim

Does this philosophy also apply to the SD40-2 Non DCC equipped locomotives? (Item 67003) I haven't taken it apart yet, but I assume that the motor still needs to be isolated from the frame. Can you use the NCE replacement for the DCC On Board  (NCE BACH-DSL) in the non DCC units?

Thanks for the link and the explanation. It really helps us novices.

Len S
[/quote]

Well It's a lot of work, but it has been done and yes you have to isolate the motor check out this install it's a pdf file I saved, it may answer your question

http://www.ppdnmra.com/decoder-inst.pdf

[jward]

not to be a wet blanket, but those bachmann installs in the link only apply to the split frame locomotives. the gp40, b23-7 and i believe the sd40-2 are not split frame locomotives. i have been installing a decoder in a b23-7, and the procedure is completely different than those in the link. when i get the time to finish it i will post some photos.

[trif]

Thank you all for your help.  I did take the GP-40 apart and the motor does seem to be isolated froim the frame.  There separate positive and negative wires running to the motor from the wheels on the trucks.  The parts list does show two different motors for the GP-40.  (One with resistors and one without resistors)  The motor in my diesel does not appear to have any  resistors attached.  Can I use this motor or must it be changed to make the DCC conversion?  Thanks again for everyones help          TRIF

[jward]

the bachmann motor is perfectly fine to use with dcc. but don't assume that because there are wires from the motor to the trucks, that the motor is isolated from the frame. use an ohmmeter and be sure BEFORE you start to install a decoder.

[richg]

Thank you all for your help.  I did take the GP-40 apart and the motor does seem to be isolated froim the frame.  There separate positive and negative wires running to the motor from the wheels on the trucks.  The parts list does show two different motors for the GP-40.  (One with resistors and one without resistors)  The motor in my diesel does not appear to have any  resistors attached.  Can I use this motor or must it be changed to make the DCC conversion?  Thanks again for everyones help          TRIF

I think what you see are two inductors. They are part of a tuned circuit, aka, filter, with the capacitors on the PC board. With no capacitors or PC board, they are not an issue.
They look just like resistors but if you compare them really close to a similar size resistor, you will see they are different. Many confuse them with Bachmann locos.

Rich