Decoder Install in an n scale lifelike SD7

I have had this little engine for several years now. Runs pretty good and now I am thinking of installing a Digitrax DZ126 decoder into it. My hardwire skills are mediocre at best. The instructions for the install that come with the decoder are pretty straight forward. The difficulty I see is locating those points to solder on the loco itself. Any hints or tips on doing this?

 

Try this: http://mysite.mweb.co.za/residents/grela/lifesd7-sd9.html.

Works good.

 

Thanks

 

I've done two of these installs, including sound. You have to isolate the motor below.

 

You've piqued my interest. Got any details you can share about a sound install?

 

Well, it's not exactly easy, I'll tell you that up front. I had to take out the rear block weight over the rear truck, make a shelf for the decoder and speaker over the rear truck, and wire it up. You have to use a multimeter to isolate the motor and then wire the DCC decoder according to directions.