Bachmann Spectrum GE 45 ton Electrical Troubleshooting

[trailsideGguy]

I'm a newbie and have been given several engines including a Bachmann Spectrum 45 ton. After cleaning and lubricating I've tried testing it out. At first one truck worked well while the other didn't move an inch. Now both don't move. I detached each truck and took it apart. Both motors and the electrical pickups from the wheels to the circuit board inside the truck work fine. However, the motor contacts inside the truck coming off the circuit board aren't indicating they're getting power from the circuit board to run the motor. Has anyone had this problem? Could it be the circuit board has been fried somehow?

 

[Rhinochugger]

The bits that sometimes give trouble are the four slim plungers (two each end) that form the connections between the bogies and the main chassis.

You'll need to take it apart - a long and painful process - and check that the springs are strong enough (they'll accept a bit of stretching) and that the pins are properly seated.

 

[trailsideGguy]

Great, Thanks! I'll give that a shot.

 

[trailsideGguy]

Hi Rhinochugger, I haven't been able to determine how to take the plungers apart to stretch the springs. Do you have any tips?

 

[Fred2179G]

The bits that sometimes give trouble are the four slim plungers (two each end) that form the connections between the bogies and the main chassis.

I'll second that. The 45 tonner and some of the geared locos are terrible. And stretching the springs won't help for long.

I suggest soldering jumper wires between the truck and the loco, which we did on Jerry's loco. If you really think you will be removing the trucks often, then install a 4-pin mini JST (XH?) plug.

 

[Rhinochugger]

I'll second that. The 45 tonner and some of the geared locos are terrible. And stretching the springs won't help for long.

I suggest soldering jumper wires between the truck and the loco, which we did on Jerry's loco. If you really think you will be removing the trucks often, then install a 4-pin mini JST (XH?) plug.

Even though I've converted mine to battery power, I still take current through the plungers. I've only had trouble when the bogie has been through an excessive amount of travel (vertically more than horizontally) and that not enough times to make me want to change the arrangement.

I've thought about it once, but it's never given me that much of a problem.

 

[Greg Elmassian]

So a bit of long-term advice applicable to may locos that have this setup.

If you get a bad short, you can dump all the short circuit current through the springs, which normally overheats them and removes the temper, and now they are weak and don't make good contact (sound familiar?) This goes for springs on the brushes on backs of wheels, and the spring in the LGB "skates"

For track powered locos, a simple 50 cent "polyswitch" can avoid this issue, and many locos actually came with them, almost all late model Aristo locos did.

https://www.amazon.com/WEFITZ-JK30-Resettable-1-35A-1-85A/dp/B0BJ8YHT92/ref=sr_1_104?keywords=3+amp+resettable+fuse&qid=1671296716&sr=8-104

Greg

 

[Rhinochugger]

So a bit of long-term advice applicable to may locos that have this setup.

If you get a bad short, you can dump all the short circuit current through the springs, which normally overheats them and removes the temper, and now they are weak and don't make good contact (sound familiar?) This goes for springs on the brushes on backs of wheels, and the spring in the LGB "skates"

For track powered locos, a simple 50 cent "polyswitch" can avoid this issue, and many locos actually came with them, almost all late model Aristo locos did.

https://www.amazon.com/WEFITZ-JK30-Resettable-1-35A-1-85A/dp/B0BJ8YHT92/ref=sr_1_104?keywords=3+amp+resettable+fuse&qid=1671296716&sr=8-104

Greg

I think the problem is the opposite - you don't get a short, it's just that when the bogey (truck) is set at a funny angle, the springs are over extended and the pins don't always re-locate properly

Well, that's my assumption

The once or twice it has happened to me, I've either taken the bogies off and re-mounted it, or just sort of fiddled about with it (technical term).

 

[Greg Elmassian]

Umm... you probably have weakened springs that do not give enough pressure to the plunger. Tell me you can be sure you never had a derailment and a short. I don't know one track power person this has not happened to. You should never have to remove the truck. Now you can get dirt/oxidation on the plungers, but that has not been reported by you.

Greg

 

[trailsideGguy]

I'm not sure of the history of this engine. The previous owner is no longer with us so I don't know what condition the engine was in when it was last used. When I first tested the engine all the lights were functional and one of the truck motors was moving sporadically. That one has now stopped and was the reason I posted the question for help.
I still haven't figured out how to remove the plungers and springs to stretch the springs. The spring and plunger housing is attached to a circuit board inside the truck (see attached). Removing the board they're attached to seems very difficult due to the gear axles. Based on the previous posts, I'm wondering if I should cut my losses and just purchase new trucks.

 

[Rhinochugger]

Umm... you probably have weakened springs that do not give enough pressure to the plunger. Tell me you can be sure you never had a derailment and a short. I don't know one track power person this has not happened to. You should never have to remove the truck. Now you can get dirt/oxidation on the plungers, but that has not been reported by you.

Greg

Ah, difficult to say that, 'cos it's converted to battery, so derailments with this loco don't give me that issue.

 

[Rhinochugger]

I'm not sure of the history of this engine. The previous owner is no longer with us so I don't know what condition the engine was in when it was last used. When I first tested the engine all the lights were functional and one of the truck motors was moving sporadically. That one has now stopped and was the reason I posted the question for help.
I still haven't figured out how to remove the plungers and springs to stretch the springs. The spring and plunger housing is attached to a circuit board inside the truck (see attached). Removing the board they're attached to seems very difficult due to the gear axles. Based on the previous posts, I'm wondering if I should cut my losses and just purchase new trucks.

No, you don't need to purchase new trucks.

The plungers go down through the chassis (footplate) and make contact with the top of the bogie. I think there must be some quarter circle (ish) contact plates for them to push on - the memory is a bit dim, because it's a long time since I took mine apart.

Just check, when you put the motor back in, that those little phosphor-bronze wipers are making good contact with the motor connectors.

Annoyingly, there's no exploded diagram on the Bachmann website

 

[Greg Elmassian]

The contact plates are the other side of the circuit board pictured, you can see the 4 arcs through the board, and you can see the feed-throughs on the tops of the boards.

 

[trailsideGguy]

Gosh guys, I'm so sorry. I've misunderstood everyone. I plead stupid newbie status (or maybe an extreme inability to connect the dots). You've been talking about the chassis plungers and springs in the first picture below while I've been thinking we were talking about the plungers and springs on the sides of the trucks (bogies) which contact the wheels (second picture). As you can see in the second picture the plunger on the right isn't completely extended, which led me to believe that was the reason why the truck wasn't operating. I thought I needed to somehow remove that plunger and spring and stretch the spring so the plunger had better contact with the wheel. Now I see of course those plungers and springs are simply impossible to remove.
What I think everyone is saying (and please correct me if I'm wrong) is my real issue is the chassis plungers are not making good contact with the circuit board feed-throughs on the top of the truck. Once I stretch the springs on the plungers, I should see both trucks operating normally - provided there's good contact between the plungers (on the side of the trucks) and the wheels.

 

[Rhinochugger]

You got it

It's not always easy describing tings without diagrams.

My experience with my 45T is that when I've had power issues, it's a lack of power coming through the plungers that's usually the issue.

 

[trailsideGguy]

Power is now very consistent to the main chassis (cab light and headlights operate normally without any flickering) but still don't have power to the motors inside the trucks. I've taken the trucks apart to make sure the bronze wipers are making a good connection with the motor contacts. Difficult to see for sure since after the two halves are connected to each other there's no way to check it out.

 

[Greg Elmassian]

cycle the switch in the firebox

 

[PhilP]

cycle the switch in the firebox

? On a 45 Tonner diesel..

PhilP

 

[Greg Elmassian]

Ha ha, got this one mixed up with the other geared loco "my loco does not run" thread.

I'll go back to my corner now ha!

 

[PhilP]

Ha ha, got this one mixed up with the other geared loco "my loco does not run" thread.

I'll go back to my corner now ha!

You're forgiven, Greg..
It is Christmas, after all!

PhilP