Lionel 8376 reverse board wiring diagram

If this is a Union Pacific Diesel, it's not supposed to have a double wound motor. It should have a 3 position E-unit.

If the motor is double-wound, you can run it from a 3-position e-unit (electronic or mechanical) by using only ONE of the two field windings.  Just tape off the un-insulated end of the other coil and leave it disconnected.

If the motor is single-wound, you can’t make it reverse with a pendulum-style 2-position e-unit.  You need a 3-position type to make it work.

The 8376 loco has the 40-0105-001 electronic reverse unit according to the service literature.

Larry

Here are some service docs

TrainLarry posted:

The 8376 loco has the 40-0105-001 electronic reverse unit according to the service literature.

I have this diesel, still new in box. I had no idea it was electronic, thought it was just like the Santa Fe version with the original E-unit.

The electronic units will eventually all fail, so it might be a good idea to replace it with the electro-mechanical 100-4 postwar type - just $32 at The Train Tender - and have a lifetime of reliability.

Thanks  to Rob, Carl , Larry, Ted. The correct # for the electronic E-unit is 40-0105-001 The engine #8376 UP A double wound single motor SD-40 mfg. 1983. My manuals show show both a  electronic or a mechanical  E units The electronic one i would like to see a wiring diagram since I have 3 in my parts cabinet.  And that is an original part. If I install a 100-004  E unit I would have to cut a hole in the frame. The wiring is not a problem. 

Hello, I also have the UP 8376 SD-40. I bought it used and have replaced the electronic e-unit. Rob, would it be possible for you to take a picture of the wiring on your unit for me? I have no idea what wires go where. I have replaced the brush plate, brushes and armature. Now I just need to melt some solder.

Thanks,

Joe

@Jhissong posted:

...would it be possible for you to take a picture of the wiring on your unit for me?

It's buried, and still new in the box, but I'm doing train stuff tonight so if I come across it I will look into it. Do the motors on these have a double wound field?

Yes, the green and red windings.

@Jhissong, if you post a picture of your board and motor(s) I can then draw on it to help you wire it out. You are using the 640-0105-001 reverse board, correct?

@Jhissong posted:

Yes, the green and red windings.

This should work then.

This is the original electronic e-unit. I had taken a picture prior to removing the board but lost it. The wires are all new. The green wires were originally brown but all of the other colors are the same as the originals. I know the white, blue and gray wires go to the lock out switch. I just don’t know which wires go to the brushes and field winding.

Thanks,

Joe

Thanks Rob,

I am just waiting on the new parts to arrive. I will post as soon as I get it back on the rails.

Hi Joe!

I too have a UP 8376 SD-40 with a failed 0105-001 electronic reverse board. I ordered an electronic e-unit from a vender on eBay, and I came to find does not work with a double wound field.

I'm wondering if you replaced the original board successfully. I'm also wondering if I can use my new electronic board by taping off ONE of the two field windings as Ted suggests.

@Don Winslow posted:

..wondering if I can use my new electronic board by taping off ONE of the two field windings as Ted suggests.

Yes, that will work.

I just purchased a Lionel 8376 that will only run in reverse and am planning to fix this only I know very little about motors and such. The 8376 I have does not "match" the wiring schematic Rob provided so I'm hoping to get some clarification on what I have. The schematic I provided is my best transposition of what is on my 8376. I know wiring photos can be problematic as well...following the leads and all. Is my 8376's motor wired correctly?

the field wire and the armature coils are wired together then the field wire is reversed in relation to the armature wire which makes the motor run in reverse this is because it's an AC motor. so, wire the armature n field like the brown wire. the electronic unit only reverses the green n red wires to make it run in reverse!

Alan

Most excellent tutorial Alan. I will have to read it slowly again (and again). I will give it a go none the less.

Update: But firstly, when it comes to electric motors I am a dunce. I have pulled the motor truck, separated all motor wires, and have had success running directly from the transformer in both forward and reverse. Now, I'm jumping the motor wires-lug-armature things to the board wires and replicating the prior "running only in reverse" with success but have yet to discover the wiring configuration which allows the transformer to switch forward/reverse. May sound crude but it is a motor break through moment for me...or at least perhaps on the cusp of such.