# Lionel SP Alco Problem please help if you are able



## Jub (5 mo ago)

We recently purchased a SP Alco deisel locomotive from eBay. The road number is 8553. I was cleaning up the pickup rollers so that they wouldn’t spark while running. So, after accidentally removing one of the rollers by pulling it out of the front truck, I went to put it back in place. I removed the shell and proceeded to go about reinstalling the pickup roller. I unscrewed the components above the front truck, spread the “u” clip and dropped the front truck to get the roller back in. This is where my problems began. I was able to get the pickup roller back in the truck and placed the truck back in its location. I put a new clip on and secured the truck back in place. When I put the components back I noticed that a wire had come loose, and for the life of me, I do not know where it goes. The engine will not run, and I’d like to attempt to repair it myself. I have a great soldering rig. I’m including pictures of the train.














I tried to lookup a wiring schematic online and it was like trying to read a foreign language. Any help would be appreciated. You can clearly see from the photos which wire is disconnecte I just need to know where to reattach it.


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## Jub (5 mo ago)

In case you aren’t able to tell it’s the black wire on the top that has come loose. It’s about 3 inches long, and I think it went down, but I’m not sure. We just want to get this locomotive back on the rails so our grandchildren can pull the PFE consist. Yes, we know the daylight paint scheme was passenger train only, but it looks great with the bright orange of the PFE cars.


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## T-Man (May 16, 2008)

You need that diagram. What helps is to trace each wire from the diagram to what you have.
First identify your parts. From left to right, there is the motor, horn, three position e unit, and the horn realy. The wire you described is from the horn relay and does not need to be connected to run the engine, It is used for the horn.
Notice the e unit. The lever connects the coil to the outer rail for it to work. The left side has a wire from the center rail, via the rollers. I suspect a short, a connection between the outer and center rail. Probably something you did when fixing the roller. Both rollers need to be isolated from the frame.
Bench check it off the tracks. One wire on the frame and the other touching that left side of the e unit. See if there is any life.
The left e unit contact is important it appears another black wire is used to connect two other black wires. One is for the bulb and the other for the horn.
Digest this, and a picture from the top and the other side may help

This was a good diagram but has an error. The two wires under the word Equipped need to crisscross locations.


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## sjm9911 (Dec 20, 2012)

Also, some of the wires look like the insulation is rubbed off. So, make sure when the shell is on the bare wires aren't shorting on anything. Best to tape or shrink wrap those.


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## Jub (5 mo ago)

Thank you for the help and diagram. I’m going to try your suggestions and let you know the results. I appreciate your knowledge on the subject.


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## JeffHurl (Apr 22, 2021)

If it's the wire with the sharpest bend in it, I believe that needs to go to ground.


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## Jub (5 mo ago)

That’s the wire I’m concerned about, the one that’s tinned and has the exaggerated bend. I’ll send it to ground. Thank you for all your help.


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## Jub (5 mo ago)

Where would you recommend I ground that wire? I’m looking at the schematic and I don’t see a clear location.


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## JeffHurl (Apr 22, 2021)

Not sure. Its the middle of three wires on the schematic. I can't tell if it goes to the horn first. Maybe it connects to the ground terminal of the horn?


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## Jub (5 mo ago)

JeffHurl said:


> Not sure. Its the middle of three wires on the schematic. I can't tell if it goes to the horn first. Maybe it connects to the ground terminal of the horn?


ive been looking everywhere for some pictures of where I should solder but I’m having no luck. Visually on the horn, I don’t see a place to solder, and on the horn mounting bracket there isn’t an obvious lug as far as I can see.


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## T-Man (May 16, 2008)

Your loose wire is on the ground side of the horn. This arrangement is different from others. Thr horn has only one wire connection, The others are ground wires on the horn frame. I have a two position set up that is close. That is why asked for pictures on the other side.


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## Jub (5 mo ago)

Here are the photos you requested.


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## T-Man (May 16, 2008)

The middle top connection on the horn relay should be connected to the center rail or left side of the e unit. When the DC signal is applied the relay will work and the battery will operate the horn.

Does the motor run now? The loose wire is only for the horn. That diagram connection makes no sense.


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## Jub (5 mo ago)

The motor does run, and the e unit selects F/N/R or just R. The loose wire is connected to the center of the what I’m assuming is the relay, but I don’t know where to connect the other end.


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## Jub (5 mo ago)

I appreciate your patience and understanding. Like I said before I’m new to this and the learning curve is steep


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## T-Man (May 16, 2008)

Center track power has to get to the relay coil. SO your wire goes to the e unit where the center rail wire is connected. This is the left side of the e unit I keep mentioning.

Notice the dip of the wire above the horn. That is where two wires cross but was left out in the diagram I first gave you.


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## Jub (5 mo ago)

Just to make sure. I’m sending a picture of what I’ve done. If I’ve solderer wrong let me know.


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## T-Man (May 16, 2008)

looks good. Now you have to troubleshoot the horn. You could test on the track but the horn may not work, The battery Plus side points to the wire side of the holder.
To bench test
If you have a wire with clips. Clip the horn wire. Place the neg side of battery on the horn. TOuch the clip wire to thr pos side. Use any 1.5 battery. D cell would be best. See if there is life.


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## Jub (5 mo ago)

Ok, everything is working as it should. One thing changed. When I flip the switch on the e unit, it’s locked into forward only instead of reverse only. Thank you everyone for all of your help and patience. I’m truly grateful.


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## Jub (5 mo ago)

The horn is dead, unfortunately, and, today is not the day for tackling that mess, when I press the whistle button on my CW80, I hear the solenoid but no sound is coming from the horn. Oh, and if any of you need help with a hobby grade R/C car, I can give you any assistance that you’d need. Once again, thank you for all your help


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## DonR (Oct 18, 2012)

You mention the loco direction with lever set:
As a 0 scale player decades ago, as I recall,
that lever on the E unit locks it on the direction
the loco is going when the lever is operated. So, if the
loco was going FWD the lever would lock it
FWD, if going REV the lever would lock it
REV. But then, I have to stop and think,
why am I in this room?

Don


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## Jub (5 mo ago)

After a very productive day yesterday, and after I get off from work today, let’s begin the process of getting the horn back in order. I can see the relay moving up and down, but no noise is coming from the horn…yet. I’ll be back on the forums after 5 central.


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## Jub (5 mo ago)

Made it home, but, honestly I’m too exhausted from a long day out in the heat and humidity. It was one of those days where just being outside sapped every bit of energy and strength from my body. I look forward to troubleshooting the horn and making this locomotive 100% operational.


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## T-Man (May 16, 2008)

It is a good sign that you see movement on the horn relay. The ground connections weaken with age and oxidation.
The mechanical fitting on the horn is a good place to start. I have a rivet connection on that base and it is loose. So I am planning on removing it. Cleaning the connection and replacing it with a nut and bolt. Sandpaper or scotch brite will work.
Old horns can go bad but may work with some tuning and extra voltage. Start with the D cell test, that minimizes connections


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