Agreed, sounds dodgy...

Dear ???

I'd agree with you. removing the decoder and testing the mech on analog sans decoder is "installer 101".
(Check the decoder documentation, I'd reckon there's probably a section which says something like "...ensure the loco works properly on analog first before installing this decoder"... )

- is the new motor mounted using the old motor gummy-rubber mounts,
or is it now glued/screwed to the chassis/frame?
(look for motor case <> chassis contact)

- Have you disconnected the motor wires, and tested with a DMM motor case <> chassis?

- Have you tested each wheel <> chassis?

- Are any of the pickup wires exposed? (glancing short to chassis)

- Are any of the pickup wires abraided, crushed, or gillotined?

If no obvious joy:
- remove the trucks as check literally pickup-wire<> pickup-wire on each truck
- if still shorted, remove and check each axle wheel<> wheel
(insanely rare, I thought there was a cast-in insulating wall in the gear-casting,
but possible the tips of each axle-set may be touching each other?)
- oddball thought, is the loco OK, but the wiring to the test track maybe causing a short?

Don't fear, this is a resolvable issue,
just gotta go logically thru the signal-path to find the "face-palm"/"d'oh" issue...

Happy Modelling,
Aim to Improve,
Prof Klyzlr

PS FWIW, NCE do a dedicated drop-on-install motor+light decoder esp for the P2K SW which works with the stock motor, was there a particular reason you elected to change motors?

Hi Prof.

The loco was running fine last time it ran on DC. I have a NCE DA-SR decoder that fits and i have tested with another loco and there is no issue decoder wise.

I decided to change the motor as the old one has minor rust on the exterior, so better to change it now then wait for a problem to arise. The trucks themselves I believe to be wired correctly, and no crushed wires as I was careful with installation. 

The test track itself isn't the issue as all other models run on it without a problem.

As you said, i will go over the loco and try and find the "face-palm" issue

Thanks again
Nick.

 

Possible Answer

I had a similar problem converting a hard wired S-4. Check that the motor mounting screw is NOT metal. Replace it even though you may have lined the frame with Kapton tape to insulate the motor from the frame. Changing to a non-conductive screw worked for me.

Suggestion For Future

Sell old locos for what ever you can get. Then buy new with sound decoders installed. In the long run you are better off. In most cases the new locos are much better. 

Very Tight Clearances

In there. Just recently added a decoder to one of these myself. Kept original motor but easy to get a wrong connection somewhere.

You'll find it and wonder why you didn't see it before.

Good Luck

Espee over Donner

Proto 2000 issue!

TCS has an online installation recommendation for this loco. No mention of a concern with motor to chassis problem. Check it out for any help it might offer.

Dante

This maybe a very basic issue

This maybe a very basic issue and I do not think it was covered but could one of your wipers be touching the frame or could you have an issue with a wheel set being reversed and sending current where it is not supposed to go? If your model has split axles could one or more of them be making contact with it's other half causing the short?

Best of Luck

Rob in Texas

Split Axles

I had a similar problem with a GP30.  Took it all apart to clean it and install a decoder. Upon reassembly, it had a short.  It turned out to be the two halves of one of the axles were touching inside the gear housing. Pretty fussy spacing. Frustrating to trouble shoot.  Grrrr 

Thankyou everyone

Thanks for all the input guys, I managed to figure out the issue with help and reminders from you all of what to look for.

When attempting to clean the trucks ect...i did pull apart the wheels and gears, as I reassembled the wheels and gears i must have pushed too much on the wheel set itself, thus creating contact with right side and left side wheels through the gear. therefor creating the shorting out issue.

I decided to run one truck at a time on the test track to try and localize the problem, after the truck that was causing the issue was identified i then took out both wheels and ran one set at a time, that's when I picked up on what the problem was

Decoder installed with new mashima motor and it runs great(very quiet), now to install some LEDs and get this thing out of the project tray

Thanks again
Nick.