Lionel 1688 wiring

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Lionel 1688 wiring
Posted by trains2353 on Sunday, October 29, 2017 2:39 PM

Acquired a very nice Lionel 1688(not an E). Headlight lites up, but no movement or e-unit noise. Removed the body; found 2 wire not connected. How can I find out were they need to go? I put some pics in if that helps. I understand there are 3 different motors in the 1688. I believe I have the 3 type. It connects to the body with 2 long screws.

Any help greatly appreciated.

http://pic80.picturetrail.com/VOL1001/4368153/24788991/413621749.jpg

http://pic80.picturetrail.com/VOL1001/4368153/24788991/413621750.jpg

http://pic80.picturetrail.com/VOL1001/4368153/24788991/413621751.jpg

http://pic80.picturetrail.com/VOL1001/4368153/24788991/413621752.jpg

 

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Posted by TrainLarry on Sunday, October 29, 2017 3:42 PM

Here is the wiring diagram for the 'E'-unit. It is the same for most engines.

Larry

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Posted by Firelock76 on Sunday, October 29, 2017 4:44 PM

You may want to consider replacing those wires, they look nasty!

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Posted by rrswede on Sunday, October 29, 2017 5:27 PM

Although Larry's statement is true, that being his schematic is the same for most engines, I am not sure it is true for this locomotive. Please look at the Olsen's Toy Train link.

http://pictures.olsenstoy.com//cd/b123/000546.pdf

swede

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Posted by TrainLarry on Sunday, October 29, 2017 6:07 PM

The different schematics have either the field or brush windings reversed by the E-unit. It does not matter what set of connections is reversed, as the results are the same.

Any motor can be wired either way with the same results.

 

Larry

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Posted by trains2353 on Monday, October 30, 2017 7:38 AM

Thanks guys! I'll be looking at the diagrams today. Wiring is nasty, but going to try and use it. Some wiring color is left, but not much.

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Posted by trains2353 on Monday, October 30, 2017 11:52 AM

After all morning, I have the e-unit working. I got the motor to hummm, but not move. Saw a little smoke from it, so stopped what I was doing. Tried to find a pic online of the motor; none clear enough to see where the wiring went. Perhaps look online for a good running chassis as the body for this one is very nice. Or send it out for repairs.

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Posted by TrainLarry on Monday, October 30, 2017 12:20 PM

Do not concern yourself with the wire coloring, as it will not match the schematic.

Identify the 2 Field winding connections and the 1 (left) Brush connection. The right Brush connection is grounded.

Follow the wiring on this schematic provided by Swede above and you should get the motor to run.

Larry

 

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Posted by trains2353 on Tuesday, October 31, 2017 9:29 AM

Thanks Larry; will try that.

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Posted by Postwar Paul on Sunday, November 05, 2017 11:40 AM

That diagram is correct. I repaired my 1688. One brush goes to frame ground, instead of the field coil going to frame ground, as in most engines.

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Posted by trains2353 on Sunday, November 12, 2017 9:27 AM

Still working on it. The wire from the pickups fell off. Will do more when I solder a new wire back on. The wire that go to the e-unit are going to be a problem to get back on. Looks like they are soldered into a small hole. Guess I need a pencil type soldering gun.

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Posted by trains2353 on Tuesday, December 05, 2017 8:57 AM

Progress; somewhat. Got the wiring corrected, thanks to another 1688. Found the part in the pic with the wire connected to it broken. I am guessing I need a new e-unit?

I know I'm spending alot of time on the 1688(2 of them now), but the bodies both are very nice(one black, the other gray) and I'd like to get them running again.

http://pic80.picturetrail.com/VOL1001/4368153/24793234/413684578.jpg

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Posted by cwburfle on Tuesday, December 05, 2017 11:51 AM

I suggest you learn how to renew e-units rather than replace them. There are some decent videos on YouTube on how it is done.

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Posted by rrswede on Tuesday, December 05, 2017 1:32 PM

I whole heartedly agree with cwburfle. I guarantee you will get a great deal of personal satisfaction out of successfully rebuilding your E unit.

Although many people replace E unit as opposed to rebuilding them, it is not necessary if you have patience, some mechanical skill and can do a bit of soldering.

Attached are two very good videos to assist you in rebuilding or repairing your E unit.

https://www.youtube.com/watch?v=C3cHF_a6CNM

https://www.youtube.com/watch?v=mA6AdfzXo3g

swede

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Posted by teledoc on Wednesday, December 06, 2017 6:56 PM

Trains2353, Just be aware that there is a progression of 1688/1688E locos, that actually use three separate motors.  Your initial 1688 is the last version, circa 1939 & later issue.  That motor is identical to a Postwar 1654 “single reduction” motor, with a Bakelite (plastic) pickup assembly.  The diagram that rrswede provided is correct.  I seriously suggest you try to learn how to rebuild the E units, and look at the provided ‘YouTube‘ videos.  If you have a question about the other versions of 1688’s, just post it.

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Posted by trains2353 on Friday, January 26, 2018 9:59 AM

Replaced the drum and all wiring plus the parts with the little copper fingers. Got that one going. Now moving to the next one.

Forgot they don't like 027 switches.

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Posted by Postwar Paul on Friday, January 26, 2018 10:44 PM

Great to hear that worked out ! That's how mine went Also, but I was able to re use the drum, but new fingers, and all new wiring.

Paul

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Posted by JimChaddsFord on Saturday, March 24, 2018 1:37 PM

Hi guys!  This is my first post so please bear with me.  I’m adding to this thread because I benefited from all the info above and took apart, cleaned and reassembled the e-unit in my 1688.  Most of the wires are brittle and show signs of vertigris, so I intend to replace them following the great wiring diagram one of you posted.  My questions are 1. Should I use 24 gauge solid wire?  I’ve been reading articles and saw that. 2. I need to get at the center rail pickup spot.  How do I get to it? Do I need to pull the wheels and take the whole chassis apart so I can solder a new wire?  Any help would be greatly appreciated. Thanks!

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Posted by TrainLarry on Sunday, March 25, 2018 12:16 PM

Welcome to the forum!

Any rewiring should be done with 22 gauge stranded wire.  24 gauge solid wire is used on 'E'-unit contact assemblies.

To change the wire to the pickups is difficult. The fiber contact shoe plate needs to come out, and you need a frame spreading tool to get it out without breaking the tabs on the plate. It can be taken out without removing the wheels, but it is difficult. Removing the wheels requires a wheel puller, and replacing them requires a press to get them on straight and quartered properly.

 

Larry

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Posted by JimChaddsFord on Sunday, March 25, 2018 1:37 PM

Thanks Larry!

You have confirmed my suspicions about removing that fiber contact shoe plate. I didn’t want to try spreading the side plates apart only to find out there was an easier way. I’ve ordered 24awg solid wire for the e-unit contact wires, which account for about 4 of the 6 wires in this engine.  I’ll use 22awg stranded for the center rail pickup and the headlight lead. I’ll let you know how it goes.

i truly appreciate your help and advice.

jim

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Posted by teledoc on Friday, March 30, 2018 3:02 AM

Jim, Welcome to the forum.  I have to ask, what version 1688 are you working on.  There are actually three versions of motors that were used from 1936-1941.  Is there enough wire from the collector plate, to add a longer piece of wire, or is it completely broken off?  If you have enough wire to resolder another piece of wire, that would be the easiest solution, and you can slide a piece of “shrink tubing“, to insulate it.  You can get a Frame Spreading Tool, from Jeff Kane, (Toy Train Tender), for $20-25.  It is a little tricky to work with, and you also need small flat blade screwdrivers, along with the tool.  I only use that tool, as a last resort, when there isn’t enough wire to add to, as above.

As mentioned, there are 3 different motors for the 1688.  The earliest is mounted with two screws, through the running boards, just in front of the cab.  The 2nd type is mounted with a single screw, that passes through the body, horizontally, just in front of the cab.  The 3rd version has two screws that pass through the body, horizontally, one near the cab, the other near the front truck.  This 3rd version, is identical to the Postwar 1654 motor.  From this description, you can figure out what version you have.  I would say most people don’t realize there are three versions.  If you have other questions about the 1688, I can answer them.

 

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Posted by JimChaddsFord on Saturday, March 31, 2018 6:53 AM

Thanks teledoc:

my 1688 has the one long screw through the body like the second version you describe. In the meantime I discovered a tool called chain pliers which are designed to spread open a chain link in the type of chain supporting a light fixture. Using these pliers and a small flat blade screwdriver I got that collector plate to pop right out. 

Before I replace all the wiring I want to test the motor by bypassing the e-unit, but I need a wire with either alligator tips or magnet (or 2 more hands) to make all the connections. Slow progress so far but hope to make some headway today!  Looks like I should connect my transformer lead to one side of the motor and one to ground, then a jumper from the other side of the motor to the non-grounded brush. Please advise if that is wrong. 

Thanks so much!  It’s great to know I have a community behind me when I’m toiling at my basement workbench. 

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Posted by teledoc on Saturday, March 31, 2018 8:10 AM

I’ll try to describe how to test the motor as simply as I can.  You will need three wires with alligator clips on each end, to test the motor.  First thing is to bypass the E unit, unsolder the two wires going to the field coil, (remember which wire goes to those connections, after you test the motor, to reconnect the E unit).  Take 1 test wire, and connect it from one side of the field coil, and take the other end of that test lead, and connect it to the brush tab, (the top tab that comes from the E unit). Take another test lead and connect that to the other field coil connection, and the other end of that lead goes to your transformer.  Take the third test lead, and that s goes to the transformer, with the opposite end connecting to the metal (ground), body, of the motor.  This is the connections you need to make.

i am assuming that you have the side rods removed from the drive wheels, before you test the motor.  Some wheels have the side rods attached with screws, & other motors have the side rods “peened” over.  With the test leads connected as described, turn the power up on the transformer, and the motor will run in ONE direction.  To reverse the direction, take the wires on the Field Coil, and reverse them.  Power up the transformer, and the motor should spin in the opposite direction.  If you’re successful with that, the motor is proven to be good!!

i can usually hold the motor in my hand, to do the motor testing as I described, but it’s a little tricky doing it.  (You swear you need 2-3 hands doing it).  After the motor is tested good, You now reconnect the E unit wires back up, the way they should be. When the motor is reassembled with the E unit, take one test lead and connect that wire from the transformer, & the opposite end to the Pickup Slide shoe.  The other test lead connects from transformer, and opposite end to Ground, (metal body).  Power up the transformer and the motor will run, as it should.  I hope you understand the explanation.  Your motor, is from the 1938-1939 vintage.  I own 18 torpedoes, of all three types of the motors used.  The torpedo locos, are the 1588 windup, 1668 (2-6-2), & the 1688 (2-4-2).  I have all the variations of the body castings, known to exist, so I can answer any question you have.

 

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Posted by teledoc on Saturday, March 31, 2018 8:16 AM

Chadd,  The wire connections, as I described above, is basically the same hookups, to test all three types of the motors used in the 1688/1688E’s.  Good luck, and if you have a question, just ask.

There is an article in the “Timeless Classics” section on this website, about the first 1688E, that Lionel made, that is different from all the others.  It describes the one version that has (Open forward facing Cab Windows), that all the later issues dont have.  That version is the Rare version.  After reading that article, I had to see if I could find one.  I did find one on eBay, and have since bought 4 more.  I own 5 of that version, and I know there are 22 more that exist.  

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Posted by JimChaddsFord on Saturday, March 31, 2018 5:01 PM

Hi teledoc: I had a productive day. Before testing the motor, I began disconnecting the e-unit and noticed one of the soldered connections on the 4-prong piece was dangerously close to the frame of the e-unit. It’s the hot wire coming into the e-unit. I bent it away from the frame then tested the operation including the e-unit.  The motor ran nicely!  I’m still rewiring  the whole engine, since the old wires break just by touching them. So far all the connections on the e- unit are soldered with new wires and the e-unit reassembled.  I’m  going to reinstall it before routing the wires from the e-unit finger pieces to the armature (2 yellows), ungrounded brush, and e-unit coil.  I tried attaching a photo but not sure ho to do that from an iPad.  thanks again for all the advice. 

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Posted by teledoc on Saturday, March 31, 2018 6:11 PM

Jim, Great that you found your problem, and it now runs.  Think about how old those motors are, and how brittle the wires become!!  You shouldn’t have a problem, once you replace all the bad wiring.  About my explanation, on testing the motor, do you understand how to do it.  When i buy a new “Junker”, to restore, the first thing I do is see if it runs.  If it doesn’t, I then tear it down to just the motor, without the E unit, and hook things up as I describe, and see if it runs.  When it does, I check the E unit out next, and replace bad wiring, do a thorough cleaning, and reassemble everything.  It takes me less than an hour to tear apart & reassemble everything.  The more you do it, the easier it gets.  Have fun is the bottom line.  If you have other questions, just ask, BUT this is Not my normal hangout forum.  I am more exclusively on Modeltrainforum.com, every day.  I just pop in here maybe once a week.  

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Posted by JimChaddsFord on Saturday, March 31, 2018 6:30 PM

Teledoc- yes I totally understand your description for motor testing and will apply this technique with the other 2 engines I’ve been given to look at and get running for a relative. I think I started with the most challenging engine first - not knowing what I was getting myself into. I’m building up my tool inventory and plan to continue enjoying o-scale train repair and operating for the years to come.  I just wish I had started sooner, as I am a newbie at the age of 60.

thanks again!

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Posted by teledoc on Sunday, April 01, 2018 11:27 PM

Jim, Its never too late to learn, and it’s really fun, getting the old Prewar/Postwar stuff running again.  I’m still having fun, and I’m 70, and didn’t even try to fix my own trains until 2008.  That was when I got the “bug”, for trains again, after 40+ years.  As far as tools, you will wind up figuring out the basic things, and a good choice is some type of Multimeter/VOM, even if it’s a cheap one for starters, (Harbor Freight).  Not to discourage you from using this forum, but you might take a look at www.modeltrainforum.com.  It is very user friendly, and a lot of good people, that can answer any question that pops up.  My only dislike on this forum, is the steps you have to go through, to post pictures.  There is really no need to have to use third party sites in order to post pictures, in today’s technology, but the software on this site, can’t do that. Anyway, it’s all about having fun.

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