help with directional short on lgb 2036 20th ann trolley

PhilP said:
Does this car have the same drive as the pignose railcar?

If so, look to the long spring-strips, which centre the drive..

PhilP
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its an LGB trolley. same basic motor block as a stainz.

After a read up on basic electronics, i think i fried a diode. which was my first thought.

i do recall running it full throttle to get it back so i could answer the phone indoors.

but having removed unsoldered each diode and still having the short, it doesnt fit.....

nevertheless, it has to be a component failure.
im just not trouble shooting the circuit correctly by pulling out diode and resistor ends. an unsoldering the light boards.

plan on getting some replacements for the lighting board diodes today, and im betting that will do it.
apparently if you fry a diode, especially the little glass ones i think , as used in the lighting boards, with excess voltage the thing melts and conducts both ways......

ill keep at it. i know ill get it, but only by frustrating trial and error...im sure its stupidly simple and obvious , but not to me.

and tried the catenary switch/setting...same short.
 
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HI again Steve, This may be a silly question but did you run just the motor block on track when you tested it out of the body? Are you sure the metal contact strips that bridge the wheel brushes and the skates are correctly positioned if you did not test it on track?
 
Greg Elmassian said:
Post #1 step #6 I think... but does not state "on track" specifically
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When I asked this same question in my post #4 it was not actually answered. Phil P. in his post #5 also assumed Steve's step 6 proved the motor block was OK. Steve says he connected power to the motor block pins in step #6. This is not the same as testing with power coming from the track. One side of the motor block's pickups are not being checked unless the motor pin and track pick-up pin on the non-common side are jumpered together. (This is an old three pin motor block according to Steve.)

I'm not saying the problem is in the motor block, just that it could be if the block was not thoroughly checked. Especially considering everything else that has been done in searching for the short.
 
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Phil, as the thing was running years without issue, i cannot imagine there is any issue with the block contact configuration. Let me know if I m missing something.

but ill jumper it later just to eliminate this factor.

i think im going to need to send this trolley out to someone smarter….wonder if it might be cheaper to buy a single 2035 trolley…? Used to see them about $100…daze of yore methinks
 
stevedenver said:
but ill jumper it later just to eliminate this factor.
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At this point I think I'd jumper the non-common motor and track pins then actually run the bare block around an analog test loop in both directions just to eliminate it and any weird motor block/track interaction as the trouble source. I'd also check that no wires are getting pinched when the motor block in installed in the chassis.
 
phils2um said:
At this point I think I'd jumper the non-common motor and track pins then actually run the bare block around an analog test loop in both directions just to eliminate it and any weird motor block/track interaction as the trouble source. I'd also check that no wires are getting pinched when the motor block in installed in the chassis.
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well phil…….
i a gobsmacked ‍

so with the block out, i jumpered white to brown, on track ,,,,,short.
i also jumpered white to green (cat). as expected nothing at all, no connection at all, no short, but motor doesnt run.

i removed the motor and attached to the copper motor contacts..runs fine, both directions
replaced motor properly seated in block, on track....short.

took a look at the plungers, wire contacts and skates. i see nothing odd. everything seems properly oriented and seated
(*&^!!

i am unable to understand how the trolley could run fine, then short, as a result of some , presumably, physical upset within the motor block involving the contacts..yet it seems this is what happened.

ill have to review the 2035 diagram and see if i find anything
 
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Just a shot in the dark here, have you thoroughly cleaned, not just inspected, all the electrical connections in the block? (And I mean clean with emery cloth or contact cleaner? I read through the posts, but didn't see that.) You may not have a short, but a high resistance connection. A tiny bit of condensation could cause that while in storage. If you can bear through a story of woe, I'll explain. I bought a 20yr old car about two years ago. Check engine light was on, but seller gave me a new O2 sensor, claiming that was the problem. Error code was low sensor voltage, need new cat convertor. I replaced the front sensor. Still had the problem. Discovered I had put rear sensor in the front. Moved sensor to rear, bought new front sensor (US$100). Still had problem. Replaced Cat Convertor (US$300) Still had problem. Working on other problems, to replace the idler pulley, I had to remove the ground strap from the engine block to the left front fender. I then recalled that I had previously cleaned a similar connection on another vehicle because the connection had high resistance causing the insulation on the wires in the fuel pump to melt. (High resistance, fixed voltage, fixed load means more amps and heat, I think.) Anyway, the connection looked good, but I cleaned that connection down to bare metal on the fender and the bolt then added a little "conductive grease" when I reconnected the wire. Problem gone, US$400 wasted! :mad: I sympathize with your frustration. Memo to self: always check for bad grounds when experiencing electrical problems in cars.
 
bad connections, like poor conductivity is not the problem, there is a short

But I think you misunderstand the wiring: there are 3 pins.. from my site:

Now I learned a few more things. the LGB motor block has 3 pins in it, two outer ones, and one more nearer one of the outer pins.

0 ---- 0 - 0 pins, showing spacing

1 ---- 2 - 3 pin number



1 is white and is the left hand rail pickup. The motor is also connected to it.

2. is brown and is the right hand rail pickup

3 is green and is the other motor pickup...


white to brown would short the left rail to the right rail... it SHOULD short !

white to green should do nothing, you basically connected the motor contacts together, nothing should happen

what you want to do is jumper green to brown.. which i think you did not do

Someone correct me if I have the pins and colors wrong, I got this from a Forney I pulled apart.

Greg
 
Just picked up on this..... you are having problems basically when trying to run on track. Have you tried running it on just a piece of track that is not connected to the layout?
Logic in this test is to confirm that some part of your layout wiring is at fault. On the layout, make sure that you don't have any rolling stock bridging any insulated gaps (now, how do I know that?), particularly if you have any form of common rail wiring.
 
Phil P:

From post #1:
6 removed motor from block, motor works great both directions.. reinserted motor into block and then attached power clips to appropriate motor block pins (old three pin style, no problems, no short in both directions.

3 pin motor block, not 4 pin...

I think my post is correct...
 
I posted as confirmation..
The pins tend to be in the correct positions for the colours.

PhilP
 
Thanks greg for staightening me out on the proper pins to jumper.

ljumpered brown to green,
block runs fine off track power
 
So with a 3 pin motor block you have 1 wire acting as common return connecting the motor to circuit board, the other side has one wire to the motor and one to the motor the other to circuit board. Both circuits have connection to wheels and pickup plungers via brass strips. Sounds to me like there could have been a crossover between the 2 wires that enter the circuit board from the motor block. Good thing is the motor is not faulty so you may need to check validity of separation between the 2 circuits. Gregs post #31 is well worth reading again.
 
I would think that if there was a crossover, it wouldnt run in either direction without a short.
since it runs in one direction fine,
and there had been no physical alteration of circuits, etc.
it has to be a component,
and,
it is my understanding that when diodes fail or are subjected too much juice they can fail

this what i think.
but…..
ive replaced and or disconnected every diode, with nochange.

ive shelved it for a bit. A bit frustrated.
i need to gather some patience and motivation to start over…..
i have plenty of other stuff that is headache free….
 
stevedenver said:
I would think that if there was a crossover, it wouldnt run in either direction without a short.
since it runs in one direction fine,
and there had been no physical alteration of circuits, etc.
it has to be a component,
and,
it is my understanding that when diodes fail or are subjected too much juice they can fail

this what i think.
but…..
ive replaced and or disconnected every diode, with nochange.

ive shelved it for a bit. A bit frustrated.
i need to gather some patience and motivation to start over…..
i have plenty of other stuff that is headache free….
Click to expand...
It's not something physical being caught somewhere when the wheels turn in one direction? A stay wire or something?
 
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