In that early version, the orange motor wire was attached to the frame near the headlight.
To avoid a short in case the wheels touched the opposite rail as a result of a derailment, it was suggested by my LHS guy to redirect the orange wire to the motor and then insulate the motor pickup.
I did that and never had a problem until today. The S3 derailed on a double slip and the wheels touched the opposite rail. That little stunt fried the decoder. I put it on my decoder tester to verify that it was dead. It was.
So, apparently, long ago I did not properly redirect the wire and properly ground it. The way I ground it was to solder the orange wire to the brass nut on the underside of the motor, and then I placed electrical tape over the soldered wire to insulate it.
If it would help, I could post a photo.
Does anyone recall from experience how to properly ground the loco?
Pete, thanks for that link. That is precisely the issue.
I am not totally clear in following the instructions on the link for the proper fix. So, maybe the best course of action is to post some photos which I will do.
The first one shows the top of the motor with the gray wire soldered to the lug. I noticed some bare wire when I snapped the photo. I wonder if that is part or all of the shorting problem.
The second photo shows the bottom of the motor with the yellow wire ( I didn’t have any orange wire when I did this work initially) soldered to the side of the brass nut. I did not solder it to the lug. Maybe I should have.
According to the instructions for the fix on the link that Pete provided, the lower motor brush is grounded to the frame by means of a wire lug attached to it which is bent so as to contact the loco frame. (You can see than lug bent outward in the photos.)
To successfully isolate the motor:
Remove the lug on the orange wire from the frame.
Cut the lug on the lower brush so that it doesn’t touch the frame and solder an orange wire to it.
Place a small square of insulating tape into the well in the loco frame where the lower brush holder sits.
Run the new orange wire up to the Lifelike 8-pin plug and replace the existing orange wire.
After reading these instructions, I wonder if my mistake was wiring to the brass nut instead of the lug. If I wire to the lug, I believe that the instructions call for trimming the lug so it no longer touches the frame. Could that be the problem?
I eliminated the 8 pin plug altogether on my two S1 locos and I also did a few S1 and S3 locos for club members. I wired in a TCS MC2 decoders. The orange wire goes right to the lower motor brush for long hood forward. For a cab forward the grey wire would go to the lower brush. Anyway you wire it make sure the lugs and the wires for the motor do not touch the frame. If a wheel hits the frame then the decoder goes poof.
My first one I posted pictures of, I went through the effort of actualyl milling the frame so I could plug in a DH163L- and keep the lights. The two I’ve done since then have been hardwired, all the Proto circuitry ripped out and the light bulbs replaced with LEDs. The rest of the install is the same. They key is cutting off that copper tab on the bottom brush cap, and also putting a layer of tape there so the cap, wire, or remnents of the tab cannot touch the frame in any way. Mine are S1’s but it’s the same frame and motor, basically the radiator housings are different on the shell.
I understand the part about curring off the copper tab and insulating so that nothing touches the frame.
But, where did you solder the motor wire on the bottom brush? Is it OK to leave the soldered connection where I had it (see second photo)? Or should I move the wire to the remnant of the copper tab?
I think I actually took the tab itself completely off - just be careful not to loose the brush spring or brush when you unscrew the cap. The tab is just a big ring connector that is threaded on the cap. WHile the cap was off I poked the end of the wire in that hole and soldered it.
Probably ok with the tab like you have it, if you wrap it with tape. In fact this very loco was pictured in Bruce Petrarca’s DCC column in the latest MRH magazine.
Guys, you need to do a continuity test between the steel body of the motor and the brushes.
You WILL find that one of the brushes is grounded to the steel frame of the motor.
What you NEED to do is isolate the entire bottom of the motor from the frame with Kapton tape and secure it with a plastic or nylon 2-56 screw. From the factory, the motor is secured with a metal screw and that is part of the electrical path to the lower motor brush.
If you dont do this, you will be blowing decoders until the cows come home.
David, thanks for that info. I will follow your advice.
The motor is secured to the frame on the S3 by a single metal screw on the underside of the frame. I assume that is the screw you are referring to which should be replaced by a plastic screw. Correct?
One other question. Where is Kapton tape most readily available? Home Depot? Radio Shack?
Kadee makes Nylon 2-56 screws and yes, it is the one that secures the motor to the frame.
I got my roll of Kapton from a customer, so I cant help you there. However, it tends to be expensive, but a roll will last you a lifetime. Just ask around.
The frame and the brushes aren’t connected to each other, at least none of mine were, that’s why the motor has a plastic end cap with the brushes in it With only one screw thought he motor can turn and put that remnent of the tab in contact with the frame, .or even make the brush cap contact the frame, hence the tape. None of this actually is a problem with this loco - until you derail and jam a wheel between the rail and frame, as happened.
My first batch of kapton tape I got from Litchfield, since they sold short lengths of it instead of having to buy the whole roll. The roll I currently have I picked up from a vendor who shows up at most of the train shows with lots of DCC parts and accessories. Most of the DCC vendors have it, I’ve never seen it in a big box store, too specialized I think. Looking back at my photos from my site, I just used a square of electrical tape, and I DID totally remove the tab. First 8 photos on my decoder install gallery. Skip the frame miulling part in the remaining photos since I cut it out to fit the DH163L0 for no reason other than I had one on hand.
You make that too easy for me with pictorial spread of the motor assembly and disassembly. [bow]
Interestingly, the text on the instruction sheet says that there are four screws on the underside, two to hold the shell to the frame and two to hold the motor to the frame. But, there are only three screws, two for the shell and one for the motor. The exploded diagram only shows the three screws as well, two for the frame and one for the motor.
I plan to follow David’s advice and replace the metal motor mount screw with a plastic one. Do you recall if you did that?
Probably to late but here is what I did for a smilar install.
I use 0.002 inch thick phosphore bronze. I have a few feet of the stuff.
Used nylon screws. I made sure the screw holes on the frame where smooth or if not, the edge of the screw hole can punch up through the Kapton tape and cause a short which one did. I found the short before powering up.
I also used the Dremel and routed the frame a slight amount to clear the PB.
