Large Scale Central

Bachmann Spectrum 2-6-0 Wiring

Electronics Power and Sound
#1

Guys, I acquired a B’mann Spectrum Mogul which had been dropped and damaged, plus someone had extensively re-wired it for battery and sound operation. (All I got was a Phoenix speaker in the tender, and a lot of connectors between the engine and tender!)

It had the usual cracked gear, so while replacing that (with a 25 tooth 2-8-0 gear again, not the 24 that NWSL suggests,) the motor came out. Underneath I found lots of wires which don’t appear to do anything.

Bmann-260-wiring-20160616_133211
Bmann-260-wiring-20160616_133211800×681 249 KB

As you can see, the connector with the 4 black wires isn’t connected to anything, nor are the red/yellow/brown/orange loose wires.

Interestingly, it seems to work, and the NMRA switch behind the (glued up) smoke box door is connected. Even the firebox glow is working. The chuff trigger is missing.

Can anyone tell me what the chuff trigger looks like? Maybe sell me one - though I can probably make one easily.

What are all those wires for? Anyone know?

#2

Wow Pete, that thing sure is a mess! I’m surprised it works. It’s ugly in there. (http://largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-cry.gif)

#3

Yea, real ugly.

First thing I would do is find out what wires aren’t connected, trace them back where they go, and remove them. Then I would get something on them open solder joints. Even if its only black electrical tape. You don’t need a dead short burning out the few good wires you have.

#4

David Maynard said:

Yea, real ugly.

First thing I would do is find out what wires aren’t connected, trace them back where they go, and remove them. Then I would get something on them open solder joints. Even if its only black electrical tape. You don’t need a dead short burning out the few good wires you have.

I’m not takng any more of this beast apart at the moment. I got it running and that’s enough for now.

You didn’t see the worst of the “ugly”. Down at the back there’s a 4-pin connector wired to the loco with additional bits of wire. Some thick, some thin, some half a 2-conductor, none longer than 2". All with nasty shrink tubing and big globs of solder.

The open solder joints in the pic are actually on top of the wheel bearing mounts (horn blocks) so they aren’t dangling in the breeze when it is put back together - they are under the bottom plate.

#5

The chuff trigger on the 2-6-0/4-4-0 is a plastic cylinder on the rear axle with 4 metal rods on it, and two metal strips coming up from the base plate to contact it. Metal rod closes circuit between two metal strips = “chuff.” (On a good day. More often, it leads to “ch-chuff” or " " because those mechanical triggers are not exactly known for reliability.) Anyway, you’re probably better served by using magnets and a reed switch. If you can drill out some 3/8" wood dowel to fit over the axle, then you can glue magnets to that dowel at 90-degree intervals to make a new chuff cam for the rear axle.

I forget–whose R/C are you using? If you’re using Airwire, you may consider using a Soundtraxx Econami motor/sound board in this loco with a Tam Valley Depot receiver. It’s got a BEMF chuff which is pretty darned accurate. That would save you the trouble of having to rebuild a chuff cam.

Later,

K

#6

Would it help if I scanned the wiring diagram in the manual and e-mailed it to you as a PDF. Note unlike other Bachmann manuals the diagram is A6 not A4 but I assume if I scan at a high enough resolution it will upscale fine. The 2-6-0 we are talking about is the “Centenial” not the little mining variant ? Picture seems to bare this out. Max.

P.S. Suspect this was a wiring burn out/short out case in the past. Some Bachmann locos have been a bit suspect in this area. I have a “Connie” that did the same from the tender up to just under the firebox. Had to replace all the wiring up to that point. Thankfully nothing forward of this point. Runs fine now (with the obligatory gear replacement too !)

#7

Max Winter said:

Would it help if I scanned the wiring diagram in the manual and e-mailed it to you as a PDF. Note unlike other Bachmann manuals the diagram is A6 not A4 but I assume if I scan at a high enough resolution it will upscale fine. The 2-6-0 we are talking about is the “Centenial” not the little mining variant ? Picture seems to bare this out. Max.

P.S. Suspect this was a wiring burn out/short out case in the past. Some Bachmann locos have been a bit suspect in this area. I have a “Connie” that did the same from the tender up to just under the firebox. Had to replace all the wiring up to that point. Thankfully nothing forward of this point. Runs fine now (with the obligatory gear replacement too !)

Max,

It certainly would help. I did a quick search and couldn’t find any such manual online. Nor an exploded view.

#8

Pete Thornton said It certainly would help. I did a quick search and couldn’t find any such manual online. Nor an exploded view.

Will do Sunday Pete. Bit busy till then. Could you message me with your e-mail or advise on how I can insert into a message here. Max

#9

Max very kindly emailed me the PDFs of the two wiring diagrams. They are quite small, and say “please use copier to enlarge” !

http://freightsheds.largescalecentral.com/users/petert/_forumfiles/misc_2016/bachmann_spectrum_2-6-0_dc_wiring.pdf

http://freightsheds.largescalecentral.com/users/petert/_forumfiles/misc_2016/bachmann_spectrum_2-6-0_dcc_wiring_from_max.pdf