Help with converting Kato SD70m

[YouraverageSPF]

Hello everyone,

So today I got a TCS K1D4-NC decoder for my Kato SD70m. After laying down the kapton tape in the correct places and installing the decoder, my NCE power cab couldn't read it. Figuring that there might be something wrong with the engine, I took the decoder out and then connected the power input terminals to the programming track via alligator clips. Even with the engine's chassis out of the picture, my system would still not read the decoder. Now, is this a common problem with Kato SD70ms, the combo of a K1D4-NC decoder and an NCE power cab, or am I not doing something right? I'll post pictures if I can.

[peteski]

I assume that you followed step-by-step instructions at http://www.tcsdcc.com/Customer_Content/Installation_Pictures/N_Scale/Kato/EMD_SD70M/EMD_SD70M.html

I assume that the decoder has the analog mode turned on by default. The easiest test is to take a 9V battery and touch it to the wheels to see if the loco (or headlights) come alive. If not, touch the battery terminals to the frame halves.  Still no movement?

This decoder only has 4 connections between the decoder and the  chassis: 2 power pickup pads on the front and 2 motor terminals in the middle.

Are you sure there is a solid connection between the power pickup pads on the front of the decoder and the tabs on the frame?  If you have a multimeter, measure the resistance between the gold pad on the decoder and the corresponding tab on the chassis.

Are you sure that both motor contacts are tucked under the copper motor pickup tabs which snap onto the decoder?



If you have 4 sets of test leads with alligator clips, take the decoder out of the locomotive and using 2 test leads connect the motor terminals to the gold motor pads on the decoder, and then hook up the gold power pickup pads on the front of the decoder to your programming track. This way you are eliminating any possible shorts.   Does the decoder work in this configuration?

[ryan_wilkerson]

I believe you need to have the motor connected also.

The problem is likely good contact from the pads in the front of the decoder. I've had problems like this with the SD70ACE.

[woodone]

I think that you have a bad connection of the decoder to the frame. Try pushing a small piece of foam packing material under the board at the front of the decoder. Make sure both motor contacts are under the decoder wing tabs too.

[peteski]

I believe you need to have the motor connected also.

That's what I said in my post:
If you have 4 sets of test leads with alligator clips, take the decoder out of the locomotive and using 2 test leads connect the motor terminals to the gold motor pads on the decoder, and then hook up the gold power pickup pads on the front of the decoder to your programming track.

[ryan_wilkerson]

That's what I said in my post:
If you have 4 sets of test leads with alligator clips, take the decoder out of the locomotive and using 2 test leads connect the motor terminals to the gold motor pads on the decoder, and then hook up the gold power pickup pads on the front of the decoder to your programming track.

Yes, our posts are 1 minute apart (there were no responses when I started typing). When I posted, it gave me the message that someone else had posted but I posted anyway, I accept the risk!