We have a case 621d that won’t start with the key switch. We have checked all fuses, relays, and replaced starter solenoid. We can turn the key on and everything comes on as it should. Get out jump starter and it fires right up no issues. Goes into gear no issues unless it is started with parking brake engaged. If it is you have to shut it of disengaged park brake turn key on get out jump starter and everything is good. My question is where do I start with this key switch issue? Neutral safety? Replace switch? I’m just a farmer that uses this to load feed and it hasn’t got any manuals with it. Thanks.
Welcome to HEF AHavens; There is a way to check park brake circuit on the machine. You'll have to scroll through the instrument cluster using the two rocker switches on right side of upper row. Do you have a operators manual or a service manual?