Model Railroading > Need help with Key Imports RS32

I have a brass Key Imports HO scale RS32 that I have decided to put DCC & sound into.  I attemped this once before, but the eletrical pick up on this loco was marginal at best.  Unit is a beautiful runner.  I decided to re-work the electrical pick up system and thus have an issue.  The motor & trucks are all sitting on a PC board with copper strips running between the trucks and the motor with plated wipers bringing power from the trucks to the PC board.  I gapped all the copper PC board runner & put phosphor bronze wipers on all of the wheel sets - hard wired all of the wipers that will eventually go directly to the decoder.    I wired it up to test on analog & all I get is a dead short.  I get a dead short even with all the wires disconnected.  I made sure all of the insulated wheels are on the same side.  Something tells me the motor may not be isolated from the frame.  Any insight appreciated as right now I'm somewhat at a loss

Wow. I know this isn't to helpful but I think your in for some quality time with your Ohm meter. Might be possible to help you if you could post a picture or two. 

When Im totally stumped, I start at square one. Pull it all apart and reassemble one step at a time checking continuity along the way.

Good luck,

Chris

Check to see if you have one set of wheelsets reversed.

Wheelsets OK - all insulated tires are on the same side -I was sure to double check this.

How many wires are going to the motor? If it's just one, then yes the motor is using the frame as a return.

Two wires - orange to the positive terminal & gray to the negative terminal.

No, you need the insulated wheels on one truck on the right rail and the insulated wheels on the other truck on the left rail.

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Why flip the wheels?  I'm curious...

So that the pickup is correct relative to the brushes to get connectivity from + rail to the + motor and - rail to - motor. 

...but if I'm using phosphor/bronze wipers on all the wheels & hard wiring right to the motor/decoder why would this matter??

Because only one side of the wheelset is insulated.  One wheel and the axle are common.  So if you have them mixed up in the truck you will get a dead short.  

One truck needs to be configured to pick up only from the left rail and the other truck needs to pick up only from the right rail.

Issue solved - remember I'm dealing with brass here & I mounted phosphor/bronze wipers on both sides of the truck & thus was providing both positive & negative polarity to the same truck and there is your dead short.  Removed a wiper from the opposite side of each truck & the unit now runs fine.  Also flipped the insulated wheelset on a truck to be opposite the other truck.  Only issue is I'll only have pick up on 4 wheels as opposed to 8, but plan to put a current keeper keep alive circuit in this unit so well see how that goes.  A friend of mine with a lot of brass experience pointed me in the right direction with this issue.  Once he explained to me what I had done with these pick up wipers, it became clear & very obvious - how could I have made such a simple mistake - live and learn...

Now that you have all that figured out, yes you can put wipers on all 8 wheels. The wipers on the insulated wheels need to be insulated from the gear box. The wiper mounts need to use plastic pads or washers for insulation then a wire direct from the wiper into the carbody. Things will be crowded to get all those parts installed without fouling the truck swing or an axle.

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Yes I do have wipers that came with the unit & were originally screwed into the gear tower using tiny plastic insulating sleeve washers - unfortunately one of these washers snapped on me & I have no replacement.  Anyone know of a source??

You might try Northwest Shortline on their website to see what they have.

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