# Reverse no Forward 356 Silver Bullet



## Old feller (Mar 30, 2012)

Gentlemen,

My friend's 356 runs in reverse fine, and nothing when in forward.

The "E unit" cycles fine, and when in the forward position moving each finger with a tooth pick on the drum to hopefully insure good contact, still nothing.

In my mind if running in reverse works then all components of the motor must be good.

So before I start tearing things apart I would appreciate your best guess or order of things to check. I have my suspicions but have learned the value of getting your insights up front.

Thanks


----------



## drbobderrig (Nov 12, 2018)

I'm no expert but does the motor act as it even has power when in forward (suggesting binding) or if acts like no power ( that would suggest still electrical issue going to the motor. I am assuming there is one motor not two in this unit. A voltmeter would help you along in the 'diagnosis'
I had one where it would run in one direction but not the other... you could tell the motor was binding. I think it was some thrust gizmos on the end of the motor shaft that were worn out making the shaft move and then bind up. When in reverse it would work find because shaft was spinning and forcing shaft in opposite direction
good luck
dr bob
dr bob


----------



## DonR (Oct 18, 2012)

You said the E Unit was operating. That indicates
that the E defeat lever is permitting it to function.
Is that correct?

My American Flyer days were way back there but I think
there are two coils in the Flyer motor that the 
E unit switches to power FWD or REV. With your Multimeter in OHMs check that both coils are solid. You should get the same
reading on both. If not check for loose or broken wires.
Since it runs in one direction and not the other you
might check the brushes. One may be worn and
not make contact in the 'other' rotation.

You can check the E Unit contacts with your meter set
to AC volts. Find the four coil connection points and
read across them when you work the E unit. You should
get the same reading FED or REV which would vary by your
speed control.

Don


----------



## Old feller (Mar 30, 2012)

dr bob, thanks. There doesn't seem to be any binding, all the side rods are off, and when running in reverse there is little movement in the armature back and forth in either direction. 
Will start checking things with a volt meter next.
Don thank you also. I believe the field is generated by only one coil as there are only 2 wires to the field coil and two to the brushes. The E unit cycles the drum very well, but I have as yet to start putting the volt meter to any thing. So from your suggestion I will first check the continuity of the field coil, then when in forward see if there is power to the field coil. Regarding the brushes, they looked to be oem in length, cleaned them up, polished the commutator surface, cleaned the grooves, put the thrust washers back as found. Cleaned the brush tubes, and the springs looked good. so I will play the electrician tonight looking for power in all the right places.
What confuses me electrically is that it seems for that motor to run in one direction would it not have to have continuity and voltage to all four connections to the motor? Then to go the other direction the E unit just switches the arrangement of those same 4 connections.
Will get back with what I find or don't.


----------



## Ron M (Mar 18, 2016)

I know very little about AF,however, I would think you could by pass the e unit and see if the motor will run. I have done this in 0 when faced with issues similar to yours. Just a thought


----------



## flyernut (Oct 31, 2010)

Sounds like a wiring issue. Check for any breaks inside the wire by using your multi-meter and set for continuity. I would start there. Also, I've had drums go bad and after replacing the drum, things all worked out..I'm still betting on the wiring. Check the wiring carefully. I just finished a 282 today that would only run in one direction, and that was forward. After checking my wiring diagrams and checking the wiring in the engine, I found 2 wires that were wrong. I switched them and the engine now just flies in both directions. Also make sure the lock-out is in the correct position.. If you still can't figure it out, send it over to me, just pay the shipping...


----------



## Old feller (Mar 30, 2012)

Yup, working now. What I learned is take someone's word with a grain of salt, even friends. What I left out describing the problem, so I wouldn't skew anyone's thinking like it did mine was: "It was running great until it fell off the table, and the forward stopped working!". Usually falling off a table doesn't do a rewire. Being assured of that I hadn't bothered to check out a wiring diagram until I started this thread.
Thanks to all of you.


----------



## drbobderrig (Nov 12, 2018)

*Falling off a table is a critical detail to leave out....*



dr bob


----------



## tjcruiser (Jan 10, 2010)

So, despite the teensie weensie itty bitty battle with Gravity, what was the actual problem?


----------



## Old feller (Mar 30, 2012)

Tj, thanks for asking.
It was the wire to the R side of the field and the R side brush were switched. ie the top L finger at the Eunit was connected to the R brush, and the bottom L finger to the R field. 
I had my suspicions of his description of how the problem started as the top finger board was loose, the soldering job looked kind of new, and twice I saw smoke from the armature. (no damage as I try to test using low voltage.)
I still would like to understand the principal of how an ac motor is reversed. How was it that the motor could run one way and not the other with such a mix up in the wiring?


----------



## flyernut (Oct 31, 2010)

oldfeller said:


> Tj, thanks for asking.
> It was the wire to the R side of the field and the R side brush were switched. ie the top L finger at the Eunit was connected to the R brush, and the bottom L finger to the R field.
> I had my suspicions of his description of how the problem started as the top finger board was loose, the soldering job looked kind of new, and twice I saw smoke from the armature. (no damage as I try to test using low voltage.)
> I still would like to understand the principal of how an ac motor is reversed. How was it that the motor could run one way and not the other with such a mix up in the wiring?


I've seen this so many times before....Back 25 years or so, I was pulling my hair out trying to figure out WHY this was happening. I finally checked my wiring job and indeed, I wired it wrong, I just had to switch 2 wires,lol.. And in fact in my previous post a few posts back, I mentioned I was working on a engine with the same problem.You do this long enough and you're bound to see almost everything, but not quite everything,lol. You learn something new everyday.


----------



## tjcruiser (Jan 10, 2010)

'Nut, etc.

I'm a Lionel guy, so essentially no experience with AF. That said, help me out ...

On a standard AF motor, is one side of the field coil grounded to the frame / rail, or is one brush grounded to the frame / rail? I.e., does the e-unit "flip" direction of current flow (I realize this is AC power) through the armature, or through the field coil?

I'm thinking about OldFeller's question / scenario ... how did it work in reverse, but not forward? I think a wiring diagram might help ...


----------



## tjcruiser (Jan 10, 2010)

Here's a wiring diagram of a standard Lionel motor that works in forward and reverse:


----------



## tjcruiser (Jan 10, 2010)

And here's a similar diagram but with wires to a brush and and one side of the field coil ERRONEOUSLY REVERSED. As you can see, the Reverse setting will work ... current flows from the pickup, through the armature, then to the field coil, then to ground. However, in Forward, the motor will not run: current flows from the pickup to the field coil, then to ground. However, the armature never sees current.

I think this explains the problem.

Cheers,

TJ


----------



## cramden (Oct 13, 2015)

tjcruiser said:


> 'Nut, etc.
> 
> I'm a Lionel guy, so essentially no experience with AF. That said, help me out ...
> 
> ...


Here's a couple of diagrams for Flyer steam engines. The 4 wire is for early reverse in tender engines and the 5 wire is 1953 until Gilbert went with a 2 step reverse unit in the cab. Note the 5 wire fiber plug is coded with a red dot since the plug will go in either way but the engine won't run, just line the dot up with the dot on the female fiber board. This allowed the smoke element to have current when the reverse was cycling. My understanding is that the current flow reverses thru the field to change direction of the motor. Hope these are helpful.


----------



## tjcruiser (Jan 10, 2010)

cramden said:


> My understanding is that the current flow reverses thru the field to change direction of the motor.


Thank you. OK, if that's the case, then my Lionel diagrams (for example) are a bit backwards. However, the example as noted is still true: mis-matched wires CAN allow the motor to run in one direction, but not the other.

Thanks,

TJ


----------



## flyernut (Oct 31, 2010)

tjcruiser said:


> Thank you. OK, if that's the case, then my Lionel diagrams (for example) are a bit backwards. However, the example as noted is still true: mis-matched wires CAN allow the motor to run in one direction, but not the other.
> 
> Thanks,
> 
> TJ


TJ, if you look at the 4 wire diagram, if you switch the blue wire with the red wire, you will only get 1 direction.I'm talking about the wires coming from the e-unit to the male jack.. These are the diagrams I use exclusively.


----------



## drbobderrig (Nov 12, 2018)

*Nice that he didn't smoke the armature....*

I didn't notice in the original post that your friend had tried a fix or two himself....I assume he didn't tell you that as well?

dr bob


----------



## tjcruiser (Jan 10, 2010)

flyernut said:


> TJ, if you look at the 4 wire diagram, if you switch the blue wire with the red wire, you will only get 1 direction.I'm talking about the wires coming from the e-unit to the male jack.. These are the diagrams I use exclusively.


Yup. It's essentially as I've shown in my "Erroneous" wiring diagram. In one direction (Reverse), both the armature and the field will be energized and the train will run. In the other direction (Forward), only one is energized, and the other is essentially taken out of the completed circuit. The train will not run.

TJ


----------

