Thanks for all the replies. I did as heavyaslead suggested and checked the switch. It was still in place and making contact, but not stopping this weird movement. It does still limit the gun carriage to only one recoil shot though when I fire the gun so it is still doing that. It's weird because I would assume it would be "all or nothing", meaning it would either stop all movement after one revolution in the mechanism or it wouldn't stop any of it anymore. So I called Tamiyausa in California and on my 2nd call I got a helpful guy who trouble-shot it with me and issued me a return number for the recoil, DMD and multi function units. I mail them out insured today. I'll keep you all posted.

TANKDUEL, your problem was exactly the same? The tank fired okay but when not shooting, the recoil would slowly cycle continously? I don't know much about the ins and outs of electronics but how can the switch still do it's main function but allow this movement?