Not in an Athearn, although if the shoulder inside the gear is worn or missing you could push the wheels together so tight the backs of the axles touch and it shorts. But those wheels would also be way narrow in gauge as well.
What you CAN mess up is if you fully disassemble it and put the trucks on backwards. But that just makes it run in reverse (on DC). Or you could put one truck on backwards - that would short the whole thing. It's pretty obvious though when both tabs on the trucks aren't on the same side. Also that woudl be a track short, and be continuous, nothing intermittant about that - set the loco on the track, short. Pick it up, no short.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Can the engine wheel sets cause a short by being flip flopped after cleaning?
cacole I pull the top part out and solder the decoder's black pickup wire to it (base)
Dr. Frankendiesel aka Scott Running BearSpace Mouse for president!15 year veteran fire fighterCollector of Apple //e'sRunning Bear EnterprisesHistory Channel Club life member.beatus homo qui invenit sapientiam
I never, ever use the Athearn headlight or light bracket. The bracket is connected directly to the frame, and if anything touches it you have an immediate short circuit.
If the lower part of the bracket seems to be firmly riveted to the frame, I pull the top part out and solder the decoder's black pickup wire to it; otherwise I cut it completely out.
Steve,
Well I have good news but it took me a long time to get here. I purchased a new decoder for the SD 40 and was determined to find out all the issues - and there were several. Here is what I did and hope it helps.
Bottom line is the loco runs quite well now - it's noisy but no more so than the other Athearn BB I have. It will never run as quiet as an Atlas but after all i did, it's okay. The only issue now is that at times it doesn't maintain a constant speed and the decoder gets quite warm - I think some CV's can be reset but for now its okay.
Finally, my min radius is 24 so I don't have that problem, but I do have a couple #4 turnouts and those are a challenge for this loco.
Sorry this went on for so long but thought the info was valuable in resolving a frustrating problem. Let me know how you are coming along.
Harold
There's never time to do it right, but always time to do it over.....
To remove the trucks from the frame you simple insert a flat tip screwdriver between the frame and the worm housing (rounded thing where the shaft goes in) and gently twist. Have your thumb on top of the worm housing when you do this or it'll go flying into the seventh reach of the unknown. Lift the worm shaft assembly off the top of the truck and the truck will fall out of the frame. On the issue of the top contact arm (red wire connection) binding against the shell, make sure the contact arm is as straight up and down as it can be and not pushed down or to one side or the other. I had the same problem with mine at first. After making this minor correction they take 18" radius curves and #4 turnouts without a problem.
HaroldA Does your harness package have new motors mounts and 4 screws.
Does your harness package have new motors mounts and 4 screws.
Hello Harold and all,I bought a new decoder and got it working again. This time things are going much better, since we've been bouncing ideas back and forth like we have. Soundwise, it's not to bad. One of the things I noticed was the headlight copper bracket was too long, and was rubbing against the front flywheel. After trimming that, it was much quieter. My motor mounts did not include screws???....However the mounts supplied with the decoder (white in color) seem to be much better than the originals in the loco. The motor seems to be fairly solid in place.
Unfortunately, now I have some other issues that can hopefully be solved. My Layout features a smaller minimum radius (22"), which should be enough to handle an SD40-2....but it appears its not for this particular unit. I've noticed that the brackets extending from the trucks (red wire connections) are restricted in their movement once the shell is on. This of course is causing the loco to bind and derail on a curve. Also, the tabs on the shell that go over the frame pins may be interfering with the trucks as well. To make matters worse, I found this out the hard way....derailment....which resulted in the loco falling 52" or so to the floor below. Ouch. Well, since its an older model, and I didn't have the shell on, the fall only broke some of my decoder connections and knocked a coupler housing out of whack. Whewww!!! So, first things first.....get a safety net for my open curved area so this doesn't happen again.....by the way, it did happen once before with a brand new Atlas GP40-2.....Ouch.....Again, thanks to Atlas, I was able to replace the shell. Secondly, getting back to the SD40-2, rework the truck brackets and shell tabs. Perhaps I can get rid of the brackets entirely and solder the red wires to the base of the trucks/brackets? Which leads me to....hate to sound stupid here, but....removing the trucks seems difficult to me. How do you do it?
All and all, if this doesn't help out with my minimal minimum radius.....off to eBay the loco goes!
I know what you mean about the Atlas - all of mine are great and the Athearns are 'clunkers' when compared to them. But this became more of a quest than anything else. I think I 'solved' the noise issue by moving the flywheels and, like I said, something seemed to click into place. It will never be as quiet as an Atlas but wanted to be able to use it.
Does your harness package have new motors mounts and 4 screws. Two of mine didn't but the one I bought today did and when I used them the motor is rock solid. I already mentioned the flywheels possibly binding if they were slightly out of position. I will try your styrene idea tomorrow and see what happens with the shell which is the next bridge to cross. That will be in the morning and i;ll let you know what happens.
HaroldA One last word on this - I promise. I looked at another Athearn harness package and found different motor mounts with screws - my other one didn't have those. So I screwed the motor down and that eliminated the rocking. I taped off the ends of the unused wires to eliminate the possibility of those touching something they shouldn't. Then I looked at the flywheels and they seemed to be pressed to far onto the motor shaft and one appeared to be rubbing against the frame when the engine ran forward. So when I moved them toward the ends of the frame something seemed to seat better - .which seems to have solved the noise issue and perhaps this was the cause of the binding. Anyway, I ran the engine - without shell - in both directions at varying speeds and everything is fine now. Steve, I hope this helps. In the meantime, if I should happen to fry this decoder, this engine is toast - along with 2 decoders.....
One last word on this - I promise. I looked at another Athearn harness package and found different motor mounts with screws - my other one didn't have those. So I screwed the motor down and that eliminated the rocking. I taped off the ends of the unused wires to eliminate the possibility of those touching something they shouldn't. Then I looked at the flywheels and they seemed to be pressed to far onto the motor shaft and one appeared to be rubbing against the frame when the engine ran forward. So when I moved them toward the ends of the frame something seemed to seat better - .which seems to have solved the noise issue and perhaps this was the cause of the binding. Anyway, I ran the engine - without shell - in both directions at varying speeds and everything is fine now. Steve, I hope this helps. In the meantime, if I should happen to fry this decoder, this engine is toast - along with 2 decoders.....
Hey Harold,I'm still contimplating purchasing another decoder for the SD40. My LHS is out of them I believe, although I could just get a different kind and solder it to the clips. But is it really worth it? I love how my Atlas GP40-2's run, and I know the Athearns will never come close to that. However, I was able to get a Bachmann Spectrum SD45 to perform well with a new decoder. My fear with the Athearn is it will be noisy, as we have seen with it so far. And where does it end? I mean, replacing the trucks/wheels is something that should probably be done also.
Something else to consider about mounting the decoder is maybe rigging a piece of styrene in the shell. When you see other newer locos with DCC, they have circuit boards mounted above the motor, eliminating any wires from interfering. My thinking is that we need to keep the wires away from any moving parts, as you suggest, by running them up above the motor, above the styrene, and accessable from the dynamic brake hatch. This should work I would think. However, as you suggest with the motor mounts, and/or motor and flywheels in general, possibly binding. Hmmm.....not sure what to do about that. Unless we are able to mount the motor differently.
Steve
Okay - I purchased another decoder and installed it in the Athearn. It runs noisily and there are two things I notice. First, the end of the blue wire is exposed and when it comes in contact with the headlight bracket or the track, it creates a short. I am thinking that if that wire wasn't properly secured inside the shell it could come in contact with the light bracket and short out the decoder. The other thing I see is that the motor doesn't sit level and it also rocks side to side and front to back. And, depending on how much it leans one way or another, the noise will be louder and softer - and will also be less in one direction as opposed to the other. Are there different sizes for the motor mounts or is this a standard part? The ones that come with the decoder do not fit in the holes in the bottom of the frame - unless they are forced. This leads me to believe that if the motor isn't properly seated and then the shell is put on, it could bind maybe almost to the point where the amps are exceeded for the decoder and it gets fried. Does any of this make sense?
Not going to press my luck tonight but these are things I saw with this latest decoder,
Thanks for all the info on this problem. I completely disassembled my SD-40 that is frying decoders right down to the gears and could find no problem at all - except for a lot of gunk. So I reassembled the engine and still had the short which only occurred when the decoder was plugged into the harness. This tells me the problem is with the fried decoder.
The one post about the decoder rubbing against the flywheel is an interesting comment and could be part of the problem. However, with the decoder sticking out of the top of the dynamic brake cover and the shell just set on the engine, it seemed to run fine and was relatively quiet. When the shell is attached to the mounting pins and the decoder still coming out through the brake cover, the engine becomes noisy and doesn't perform as well which tells me two things - either the shell is binding, and maybe has from day one and wasn't a problem when run on DC, or the harness wires are causing a problem as they may be binding between the flywheels and the shell. This is unlikely. So my conclusion is a combination of two things - the shell is binding somewhere against a flywheel (and one of mine does have a chewed up edge) and/or the decoder was also binding because it wasn't attached to the brake cover.
I guess I am game to buy another one, reinstall it, tape it to the dynamic brake cover, route wires so they are not near the flywheels and see what happens. But if I fry another one, this SD-40 will become parts. All my other BB engines run fine and since this problem is peculiar to the SD-40 it also makes me wonder about a basic problem with its design. Again, highly unlikely, but it at this point nothing would surprise me.
That "One direction only" part on DC is probably the clue - if it only goes one way on DC with the decoder installed, then there is a blown transistor in the motor drive.
retsignalmtr Since the decoders can be run on DC as well as DCC try it on a DC system first. If it doesn't run, remove the decoder and try the loco on DC or DCC on 0 to see if the loco runs with and without the shell on and how much noise it makes. Double stick tape should hold the decoder ok. I keep several locos on the rails and when I turn on my track power and none of them jump. Did you just use tape or did you bend up the pointed thingy on the bottom motor contact to isolate the motor. Sometimes that pointed barb on the motor contact will pierce the tape after a while.
Since the decoders can be run on DC as well as DCC try it on a DC system first. If it doesn't run, remove the decoder and try the loco on DC or DCC on 0 to see if the loco runs with and without the shell on and how much noise it makes. Double stick tape should hold the decoder ok. I keep several locos on the rails and when I turn on my track power and none of them jump.
Did you just use tape or did you bend up the pointed thingy on the bottom motor contact to isolate the motor. Sometimes that pointed barb on the motor contact will pierce the tape after a while.
I am able to get the loco/motor to work on my DC test track with the decoder installed. But only in one direction. Why would it work on DC and not short, yet it shorts out on my DCC layout, where I have other trains running fine?
I am surprised some of the main people have not answered this question. Guess I wore them out while I was trying to do the same thing.
OK, Steve have you done a stall test to see what amps the old BB motor stalls at? You will need a volt meter and DC power pack. Pull the motor out and gap a flywheel and start stalling it. Make sure it is warmed up before you full stall the motor. If it stall at more than 1 amp, I would remoter the engine. I cooked 3 decoder on a motor that stalled at 1.35 amps. Would run for 10 hours or so, but would still let the smoke out. Digitrax decoders I was cooking was rated at 2.0 amps peak, but peak is a mill a second. (sorry about the spelling)
If you have to save the engine I would remoter. Try this company. They make there own motors and are helpful.
http://www.alliancelink.com/alp/
Next, with the frame still being hot, do not set the engine on a live track! Shut down the DCC system first, then set the engine down! I cooked a few while cleaning the wheels.
As much as I love my old BB engines, I will never convert one to DCC again with out a low power draw motor. Sooner or later it is going to let the smoke out of the decoder.
These are just the ones I saved. NCE will sell you a new decoder for $10.00 for ever smoked one you send them.
Cuda Ken
I hate Rust
What I usually do is tape the wires to the top of the motor and have the decoder hanging off the back of the motor over the flywheel. But I use a much smaller decoder. My decoder of choice is the Digitrax DZ125. It's made for Z Scale applications but is robust enough for HO Scale equipment. I have them in a pair of SDP40F's that I run. One's on an Athearn BB SDP40 frame and the other is on a Proto 2000 E6 frame. Both (they're permanently consisted together) can run all day long without a problem pulling a 25 unit train with a GP40 helper 11 cars back, also using a DZ125. I have around 20 locos that are equipped with them.
Or I could do what jeffrey-winberly is suggesting about the housing....maybe use double-sided tape or something.
retsignalmtr Your decoder is probably shot. You can destroy them even without making smoke. When you replaced the shell did it cause the decoder to press down on one of the gear towers or flywheels? If this happened the pressure could have caused the motors current to go up and maybe pass the stall current level of the motor which could have passed the maximum current rating of the decoder. I had more noise with a blue box SW1500 until I moved the decoder into the roof of the cab.
Your decoder is probably shot. You can destroy them even without making smoke. When you replaced the shell did it cause the decoder to press down on one of the gear towers or flywheels? If this happened the pressure could have caused the motors current to go up and maybe pass the stall current level of the motor which could have passed the maximum current rating of the decoder. I had more noise with a blue box SW1500 until I moved the decoder into the roof of the cab.
I wonder if that is part of the problem....the decoder being shot already. Would you say that by simply setting the loco on the track, and turning on my DCC controller power (Bachmann Dynamis) the loco gives a little jolt which triggers the DCC controller to signal "short circuit", that that would be considered a "fried" decoder? If so, then like you mentioned, I need to be very careful of the placement instead of just stuffing it in there. Maybe rig a piece of styrene in between the dynamic brake hatch and motor to protect it. Or am I wrong in all of this?
If your SD40-2 is like mine it should have a dynamic brake housing that comes off. The decoder can be secured to this cover and be well above the motor.
I know. Like I said, mine ran just fine without the shell - but as soon as I even set the shell on the frame without securing it, problems started. Now when I did this, I had the decoder sticking out the top of the shell but as soon as I moved the decoder, the grinding started again and the decoder was fried - and at $21 per decoder this was an expensive experience in trial and error. I am with you in totalling disassembling the entire engine and looking for something - anything - that would solve the problem. Let's keep in touch on this one...
HaroldA Interestingly enough I have the same identical set of problems with an old Athearn Blue Box SD40 which I affectionally call the "Athearn Grinder." (See the posts on the General Discussion tab.) Mine ran fine for a while with the Digitrax DH1234T but when I put on the shell is when all the problems started - noisy running and short circuits. I thought I had found the problem in the black wire connection but that wasn't it either. Oddly enough when I would disconnect the black wire and touch it to the light bulb connections the bulb would light but when I would touch the black wire to its connection point in front, I would get the short. So far I have fried two decoders so I am at a total loss. Let me know if you, or anyone else, can come up with some ideas.
Interestingly enough I have the same identical set of problems with an old Athearn Blue Box SD40 which I affectionally call the "Athearn Grinder." (See the posts on the General Discussion tab.) Mine ran fine for a while with the Digitrax DH1234T but when I put on the shell is when all the problems started - noisy running and short circuits. I thought I had found the problem in the black wire connection but that wasn't it either. Oddly enough when I would disconnect the black wire and touch it to the light bulb connections the bulb would light but when I would touch the black wire to its connection point in front, I would get the short. So far I have fried two decoders so I am at a total loss. Let me know if you, or anyone else, can come up with some ideas.
That's what is driving me crazy about all of this?! I mean, I had it running for a short while...although noisy, it still ran with the Digitrax DH123AT decoder. Then all of a sudden the problems came. I have the motor compartment isolated with black electricians tape, and even went as far as removing the motor entirely from the frame with the wires attached still. And it still shorts out. I have all of the hookups done properly (red - to each truck, black - to front truck/headlight bracket, etc...)....My next thought is to take apart the trucks entirely and see if it does anything. Otherwise maybe I just yank out the motor entirely and make it a dummy. I don't really want to do that though. It's got to be something simple/stupid.
I have been purchasing old Athearn BB SD40-2 on Ebay to expand my KCS fleet. Some of the locos I am taking the motors out to make them sound only. The ones with motors I have used the DH123AT and others I have hardwired with a regular DH123 with good results.
Check your KDs to make sure they are not grounded to the frame. The KDs need to be fully isolated and not grounded to the frame. Also make sure the KD trip pin is not dragging on the track as this can short things out too as the Athearn frame is hot.
Jim, Modeling the Kansas City Southern Lines in HO scale.
Make sure the electrical tape covers all of the bottom of the motor well. Did you put the conducting strip from the trucks to the motor back on? If so, take it off. Your decoder wires should be (if I'm not mistaken) red to the tops of the trucks, black to the bottom of the trucks, orange to the top of the motor, gray to the bottom of the motor. At no time should the orange or gray wires make any contact with the frame. Make sure there's a point on the solder on the motors bottom clip pushing through the electrical tape.
Steve boy I know the feeling. Make sure the wheels are not hitting the frame, it is still hot! Check the flywheels as well, touch the fame, short! Pull the shell and try again before you let the smoke out of the decoder. I BBQ a lot of decoder get the hang of it.
Best way is to make the chassis none power. I am sure David B will fill you in on how to do it.
Smoke them if you got them, Ken
I'm upgrading an old Athearn Blue Box loco (SD40-2) to DCC using the Digitrax DH123AT Decoder, along with upgrading the couplers with Kadee #37's. I thought all was going well and had it running without the shell on. But once I put on the shell the problems started happening...(1) the loco seemed a LOT louder (2) and now I can't get it to stop short circuiting on me. I disassembled the loco, going as far as dismounting the motor, and it still shorts out on me. I made sure the bottom tray where the motor sits is isolated (electrical tape), and all of the wires/clips are in place, but still nothing. Can anyone suggest anything for my problems?
Thanks,Steve