LGB Coach electrical problems

J

John Ward

Registered
I need advice about electrical problem with my LGB 3167 2nd class Rhaetian Coach. The pair have been packed away for 30 years and I have run them today. One is OK, the other causes 8 amp overload when placed on the track. The other is fine. I have ckecked the wheel pickups, wiring, lighting circuit board, all connections but no obvious cause. What is the potential cause?
 
John Ward said:
I need advice about electrical problem with my LGB 3167 2nd class Rhaetian Coach. The pair have been packed away for 30 years and I have run them today. One is OK, the other causes 8 amp overload when placed on the track. The other is fine. I have ckecked the wheel pickups, wiring, lighting circuit board, all connections but no obvious cause. What is the potential cause?
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There is obviously a short circuit somewhere..

It could be a bulb has failed and gone short-circuit, but doubtful.

It could be a bulb-holder has twisted, and shorted the wires.

Start by removing the bulbs, and giving the wiring another good visual inspection.
Try it without the bulbs..

PhilP
 
PhilP said:
There is obviously a short circuit somewhere..

It could be a bulb has failed and gone short-circuit, but doubtful.

It could be a bulb-holder has twisted, and shorted the wires.

Start by removing the bulbs, and giving the wiring another good visual inspection.
Try it without the bulbs..

PhilP
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Hi PhilP - thanks for your prompt reply. When I stripped the coach, I isolated the board containing the bulbs and they all worked fine when connected to power. There are no obvious signs of failure on the circuit board. All connections are firm, no burnt or loose wires. Wheel connections are positive. I will strip the good coach and do a comparison as a last resort to see if any manufacturing faults may be the problem.
JohnW
 
In which case, it sounds like a problem at the bottom end.

Examine the wiring from the pickups. Especially where it enters the carriage..

PhilP
 
A friend of mine was running a new one of these coaches last week on my railway. At the circuitboard, The wire from the wheels to the circuit board was stripped back a little for far and was causing the short.

Does it still create a short when the lights are 'off' using the switch? If yes, it would suggest the problem isn't the lights but around the PCB to the wheels.
 
I would also be tempted to remove the wheels from the bogies and test each one for correct electrical function, nit unknown for LGB wheels to go short circuit but somewhat rare.
 
curtis said:
A friend of mine was running a new one of these coaches last week on my railway. At the circuitboard, The wire from the wheels to the circuit board was stripped back a little for far and was causing the short.

Does it still create a short when the lights are 'off' using the switch? If yes, it would suggest the problem isn't the lights but around the PCB to the wheels.
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Hi Curtis - the short is still there when the light switch is off. I will take a closer look at the circuit board connections.
 
John Ward said:
Hi Curtis - the short is still there when the light switch is off. I will take a closer look at the circuit board connections.
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dunnyrail said:
I would also be tempted to remove the wheels from the bogies and test each one for correct electrical function, nit unknown for LGB wheels to go short circuit but somewhat rare.
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Hi JohnD - I have removed the pickup wheels and tested their electrical isolation, both show no reading of isolation breakdown. I will keep looking for a solution.
 
Both sets of wheels are wired the same way round, I assume?
Left-to-left, and right-to-right?

That is an easy mistake to make..

PhilP
 
Good news all - I have found the problem by opening up the good coach and comparing it with the problem one. A pair of wires from each wheel pickup terminate on the on/off switch circuit board. Two of the terminations are marked with red dots, the other two unmarked. The wheel wires were connected in pairs at 12 o'clock and 6 o'clock connectors. On the operating coach, the wires were connected in pairs at the 3 o'clock and 9 o'clock connections.
When reconfigured, the short circuit was removed and after reassembly, the coach ran perfectly.
Thanks to all for help and inspiration.
 
John Ward said:
Good news all - I have found the problem by opening up the good coach and comparing it with the problem one. A pair of wires from each wheel pickup terminate on the on/off switch circuit board. Two of the terminations are marked with red dots, the other two unmarked. The wheel wires were connected in pairs at 12 o'clock and 6 o'clock connectors. On the operating coach, the wires were connected in pairs at the 3 o'clock and 9 o'clock connections.
When reconfigured, the short circuit was removed and after reassembly, the coach ran perfectly.
Thanks to all for help and inspiration.
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Aha so Phil got it right, well found and sorted.
 
Glad you found the problem by yourself.
I once had a caboose that I bought on Ebay (American 4 axle bobber) and shorted the track power. There were no wires or electronics on this caboose. What I found is the original owner had removed the axles and repainted the wheels with a silver paint. I cleaned the paint off the plastic at the wheel and no longer had a short. The paint had electrical continuity and created the short.!!
 
Dan said:
Glad you found the problem by yourself.
I once had a caboose that I bought on Ebay (American 4 axle bobber) and shorted the track power. There were no wires or electronics on this caboose. What I found is the original owner had removed the axles and repainted the wheels with a silver paint. I cleaned the paint off the plastic at the wheel and no longer had a short. The paint had electrical continuity and created the short.!!
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He/she possibly likely used conductive paint used to create a high (low) resistance link to operate auto functions with DCC. I imagine the full repaint would have been enough for a full short, in 00 only a small line of the stuff is required between the wheels.
 
Dan said:
Glad you found the problem by yourself.
I once had a caboose that I bought on Ebay (American 4 axle bobber) and shorted the track power. There were no wires or electronics on this caboose. What I found is the original owner had removed the axles and repainted the wheels with a silver paint. I cleaned the paint off the plastic at the wheel and no longer had a short. The paint had electrical continuity and created the short.!!
Click to expand...
Hi Dan - we all buy at some time, preloved items for our railroad and inherit the occasional problem. My carriage problem was obviously someone else's problem that they found too hard to solve. Their loss, our gain. Often simple solutions stare us in the face.
 
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