It's a Thomas 85 actually,{first mistake) with a Kubota D722. I've had this problem for years and now cant get it to turn over. I used to be able to jump start with a booster or from my truck but that doesn't even work any more. I turn the key and it just clicks. This all started when I had a friend / mechanic work on it. We added a key pad after someone attempted to steal it. So far I have replaced the Ignition switch, the battery, the alternator, pulled the starter and tested it, chased the wiring all over. Everything checks out but it just wont turn. On the rare occasion in the past when I could get it running all the electrical will shut off, but the engine keeps running. Very frustrated! If anyone has tried to work on one of these, you know how tight access to anything is. All help is appreciated.