Heritage 2-8-8-2 what to do. I'm at a loss


kjchronister

kjchronister

Member
So my beloved heritage 2882 is toast.

Sounds work. Lights work. No motion. I've swapped in known - good decoders and no difference. It's not the decoder. I put in a dc blanking plate, same: no go. I used wires from a dc power supply direct to the motor terminals and it ran like a champ. I've checked all the wires, harnesses, etc. All good. But no matter what I do, something is keeping this thing from the motor running.

I'm about ready to give up. Done everything I know. According to every ounce of my 30-some years mrr experience, and my multimeter, it should be running. But no dice.

Any recommendations for who can help? I'm done. At this point my options are find someone better than me to diagnose/fix, sell it for peanuts as a non runner on ebay, or just relegate it to the display case...?

It's been one of my best locos for years, and I hate to see it go. But I'm past my ability to do more and no idea what's next.
 
Is the driveline free? Is the motor trying to turn but something is stopping it? It could still be the decoder. Maybe the motor needs more current than the decoder can supply?...
 
It sounds like one of the wires in the multi-plug from the tender to the engine has broken. There are several wires on either side of the plug.
 
When you "checked" the wires did you check resistance or just continuity..........if the wire is multistrand and a bunch of the strands are broken, it would still check for continuity, but may not pass enough current to turn the motor.
 
Driveline turns very nicely, no binding or notable resistance.

All the wires/connector check out. But mrldave is right, I just checked continuity. Will go check resistance...
 
You have to check the drive output on the decoder as well. I have had a LokSound fail, but on sound...not the drive. There's no reason any other decoder can't fail on the drive output but retain its amp and sound files. If the electric circuits all check out, every single relevant one of them, then look for a broken coupling or universal or gear. Failing that, the motor might be toast.
 
I know it's not the decoder, as I have literally swapped in two other decoders that worked fine in their respective locos, both before and after trying them in the 2-8-8-2, and they produced the same result while in it: Sound and lights, no 'go'.

I also know the motor works because I've tested it with leads directly to the motor, and it runs like a top. I know the drivetrain works, because the motor was in the loco when tested, and drives the drivetrain/wheels/connecting rods et al just fine.

It's pretty clearly something electrical somewhere. I'll go to resistance testing as suggested and go through it -again- to see if I've missed something somewhere.
 
Well between the decoder and the motor is the socket and the wires - the problem has to lie there.
 
Well, we were all wrong. Me most of all.

BigRailNut had it closest, but not exactly. In any case it's really weird what it was - a sort of "perfect storm" of diagnostics gone awry that hid the problem.

Sit back, it's worth a read. You may be next...

So... this all started because the headlight had quit working... Immaterial, I thought, once the whole thing exploded on me. As it turns out, failing to recognize/mention this was at the core.

When I pulled off the shell, I found the headlight leads were attached by putting the wire through a hole in the circuit board, and mashing on a plastic "shoe" to hold them in place. Like this:

20141013_150414.jpg

Since the headlight is on the leading engine which swivels, but the connection is on the circuit board which is 'fixed' to the back of the loco, these wires move as the lead engine swivels. Over time, one had pulled out from under the shoe.

I 'tsked' at the bad engineering, and soldered the wires in place solidly. Went to put the shoes back on just 'why not' but they no longer fit over the solder. I tossed them in my useless bits pile.

So, I put the shell back on, put the loco on the track, and you know what happened then: no-go.

Since then I've gone through all the steps I outlined above. I also tested the resistance on all connections since last post - all good.

Let's take a look at the loco while I was doing this:

20141013_150240.jpg

Shell off. You can see there's a circuit board on top (held on by one screw) and the motor, flywheels and transmission are sandwiched within two weights - an upper and a lower. The upper weight is held on by two screws.

One key thing I did several times during the process was take off the upper weight so I could test the motor and transmission by applying jumpers from my benchtop 12v power supply right to the motor terminals. As previously stated, it ran fine. Turned the wheels, no binding. If I set it on the workbench and applied power... away it would go.

So I screwed the top weight back on. Tested everything else: continuity all the way back to the decoder, that power was coming over the circuit board to the wipers that supply the motor power, etc. All good. Everything checked, the decoder was supplying power to the motor, the power was reaching the circuit board, the wipers and all. But no-go.

ARGH!

Went through this process several times, trying all your suggestions. Looking for a connection I hadn't tested, etc. More and more frustrated.

On the last attempt, I tested resistance of everything as had been pointed out I missed. Again, no problems. Just pro-forma, pull the upper weight again, apply power to motor, and everything goes. Let's try running it one more time.

IT'S ALIVE!!! It was moving. Haltingly and badly, but it was turning the loco. What was different???

The only difference I could even think of was that in my frustration, I hadn't tightented down the top-weight screws this time...

Okay... pull it all apart. I'd suspect I mismounted the motor or something, but I'd never actually removed it. Maybe while I was running it with the top weight off it misaligned??? Okay, rip it ALL apart. Guess what I found? This:

20141013_145947.jpg

One of those damned little 'shoes' had found its way under one of the flywheels. I could have sworn I threw 'em both in the trash pile, but I guess not... When I took the top shell off and there was plenty of 'wiggle' room, it didn't matter: the motor ran, the transmission ran, the wheels turned. When I tightened the screws back down, it bound up that flywheel against that plastic bit and 'no-go'...

I'm not sure whether to feel stupid that I lost track of that bit, or damn Murphy's eyes for getting me again.

But... It's alive.
 
BigRailNut said:
I've had that happen with RC trucks. While it's apart everything is good but once reassembled something binds....
Click to expand...

Yeah, I've got a Traxxas where that happened too. Shattered the rear scuff plate driving too 'spiritedly'... and after I installed the new one it didn't go correctly. It was a sliver of the old broken plate stuck in the suspension...
 
kjchronister said:
Yeah, I've got a Traxxas where that happened too. Shattered the rear scuff plate driving too 'spiritedly'... and after I installed the new one it didn't go correctly. It was a sliver of the old broken plate stuck in the suspension...
Click to expand...


I had a suspension pin bind on my SC-10. Turned out it was bent enough that the suspension wouldn't work on one side...
 
kjchronister said:
Well, we were all wrong. Me most of all.

But... It's alive.
Click to expand...

You said that with a decoder it didn't work (and you tried more then one) but DC power to the motor worked - correct?

I don't understand how the problem you found didn't effect both situations.
 
Dc power applied directly to the motor contacts by hand worked... but only as it turns out because I had the weight removed while doing so and the flywheel thereby wasn't bound up by the little plastic bit.
 
kjchronister said:
Dc power applied directly to the motor contacts by hand worked... but only as it turns out because I had the weight removed while doing so and the flywheel thereby wasn't bound up by the little plastic bit.
Click to expand...

Ah... I see.

Just out of curiosity did you ever try running it with the decoder under the same conditions - no weight?
 
No. I only had to remove the weight when I was accessing the motor terminals to test if motor/driveline was good with direct power right to the terminals: and being a bit of a neatnick, I always replaced the weight after I did that; so all decoder tests were done with the weight on...

That is until the test where I had got frustrated/sloppy and replaced the weight, but didn't screw it back down. THEN it moved (jerkily) via DCC, which then led me to just disassemble the whole bloody thing (and find the plastic bit under the flywheel).
 
Wwhen I put power to the leads that go to the drivers
It runs flawless but if I use the powers leads on the board it doesnt move
 
As I well know, that could be several things :-(

I would start by texting all connections from the tender forward. Do the connections from the board in the tender show 0 resistance to the pins in the plug receptacle, etc. Then test if the wires are good from the plug at rear of engine to the connections to the engine board under the shell. I believe the 2nd and third wires feed the motor, so check from those to the wipers.... make sure the copper wipers from the board that go down to the motor contacts are properly inserted and in contact.

Are you dcc? Bad decoder is the most obvious potential issue there.
 
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