Installing a decoder in the Bachmann 4-6-0

[sizemore]

I picked up the Bachmann 4-6-0. Its nice but I want the smaller tender because it just looks better. So I picked it up at the same time. Looking at the directions for the 4-6-0 it's equipped with a 28 step decoder, this won't fly; I decided to add a Digitrax DZ125. Again following the directions it states to split the board in the tender and solder per the directions. Installed it in the new tender and I threw it on the layout -no lights, no-Go. I'm aggrevated, my solder joints were hot, and the decoder is brand new. I'm sure if omitted the board and wired it direct I'd be fine, but I wanted to avoid a rats nest of wires. I'm wondering if I may be missing something that is not on the directions. With the Class J decoder installation required the removal of a resistor to allow the decoder to finction normally, just wondering if the solution to my problem may be the same.

See post #5 here: http://www.trainboard.com/grapevine/showthread.php?t=88037&highlight=sound+install+Bachmann+%28dialup+warning%29







Thanks,
The S.

[sizemore]

hard to tell from the photo.
is the wire from the tender pick-ups red wire to the right side of the tender?
it look like the red wire is in the left side.

that would cause a short anyway.
v

Red - Right, Black - Left.

The S.

[victor miranda]

btw, I like your idea.   I may steal it.

I guess I would test all the the leads from the loco at this point.
after I removed the decoder.

next I'd test that the board makes the proper connections
to the solder pads.

motor + and - should be 20-ish ohms

left and right should be infinite.... or close to zero if you are testing from loco to tender.

eliminate all the possibilities until you have only one left....

victor

[sizemore]

btw, I like your idea.   I may steal it.

I guess I would test all the the leads from the loco at this point.
after I removed the decoder.

next I'd test that the board makes the proper connections
to the solder pads.

motor + and - should be 20-ish ohms

left and right should be infinite.... or close to zero if you are testing from loco to tender.

eliminate all the possibilities until you have only one left....

victor

I'll put a voltmeter to it tomorrow see what readings come out of it. I wonder of the RF limiters (the coils) would have any affect on DCC signals hence why whomever did the J install bypassed them.

The S.

[victor miranda]

the coils are called rf chokes.

I believe they are to supress the rf noise from the motor.

luck on the install.

victor

[wm3798]

Did you test it before you started the surgery?
Lee

[sizemore]

Did you test it before you started the surgery?
Lee

No, but in my defense it was brand new never openned. I've done about 30 installs and have never had a DOA that I can remember. Getting ready to put a VM upto it to see whats going on. I picked up another DZ125 this evening so....

The S.

[wm3798]

Fool.  With Bachmann it's always "Trust, but Verify"

[Insert purloined image of Ronald Reagan wagging his finger at Gorbachev]

Lee

[sizemore]

Heh. Well I won. It's working now. Ohms on Grey/Orange, check. 7 volts on Red or Black/Ground, check. Angrily I stuffed my thumb on the tender contacts. Our little engine that could...did. It moved. Lifted my thumb...engine couldn't. Pressed thumb again, it went. Confused I took very close inspection of the contacts. There was the most minute gap of gaps, like hair of the teeth gap between the contact strips and the truck contact finger. On inspection of the trucks from both the Medium and Small USRA tenders the fingers are infact different they are longer on the Small tender. I must've used the Medium tender trucks in the Small tender, so I swapped and all is well. Now I just have to get the tender shell to sit properly and were good to go.

What this does mean is that the locomotive does nothing and relies solely on the tender for electrical pickup, as far as I can tell without further investigation.

The loco runs ok but the rods may need some adjustment, I'm getting a hitch in the motion at a given speed range, but that will probably be something rubbing where it shouldnt.

The S.

[sizemore]

For reference:



Gotta modify the drawbar but this is a start.

The S.

[woodone]

I will bet that the wires running between the loco and the tender (one red-one black) go to the loco's right and left rail wheels.
Before you added the decoder you should have rang them out, to see what was what.

[sizemore]

I will bet that the wires running between the loco and the tender (one red-one black) go to the loco's right and left rail wheels.
Before you added the decoder you should have rang them out, to see what was what.

I'll bet you $20 the red from the loco is not a pickup wire from the loco.

The S.

[woodone]

Well, I would guess that you rang the wires out - right?
No, I will not wager with $20.00 that which I can not see.

[sizemore]

Well, I would guess that you rang the wires out - right?
No, I will not wager with $20.00 that which I can not see.

None of the wires from the loco were changed, they are connected to the stock PC board which I left unchanged except for removing the DCC board. The red wire in the picture is actually the positive motor lead, you can see the M+ in the first picture. The problem experienced was a result of using the wrong trucks with the tender chassis.

The S.

[woodone]

Well I can see that the red wire is labled M+. Other than that,  I can not see any other wires that I can ID. othere than the one marked R
The reason I bring this up is - If there are only two wires needed that is what you would find, not the 6 that I see.
The wire that is next to the M+ on the board I see a wire and terminal that is marked R. Does not this wire go to the right wheels on the loco?
You may have got the wrong trucks mounted at first,  but I still think that the locomotive picks up power from the rails.
Could be wrong and it would not be the first time.
I just can't picture Bchmann using any more wires than needed.