I damaged this decoder and sent it to Zimo for repair. It came back with a 6 pin plug on it. I tested it on my MXTAPS and it worked OK. I de-soldered the wires I didn't need, leaving the red, black, orange,grey and speaker wires. I also soldered Lais stay alive wires to the positive and ground pads. Not the capacitor pads. I found a 6 pin socket and soldered the pickup and motor wires to it and all the rest connected directly from the decoder as above. I used a very fine stranded wire 36awg I think to go from motor and pick ups to the speaker, decoder and stay alive in a wagon and made sure that none were pinched or shorted. This loco is a Dapol B4, so hardly any room inside.
Now for the problem: This loco runs superbly... when it runs, but it seems to have a mind of it's own. I can use it and then go and do something else. Come back to it in a few hours or next day and nothing. I get Lenz error, 2 no connection on the programming track. Come back again and away it goes with perfect sound and running. I've stripped it down and checked the wiring with a multi meter and found no damaged wires or dodgy joints. I've run out of ideas and hope someone can come up with something.