I have an IH 966 with a battery drain. IH mechanic told me to take off the ground cable and scraped it across the negative post. Did and have confirmed I have a short somewhere in the system. I unhooked the two wire plug and positive cable on the alternator with everything turned off and that stopped the sparking on the ground cable. So I bought two new batteries (old ones were done for after too many drains) and a new alternator. I have installed the new batteries and alternator to find out that even with these items new I still have a drain using the negative post testing method with the alternator wires plugged in. The lights to the tractor are not connected and I have installed a new key switch. Could it be the starter solenoid is shorting out and causing this? What else would have live power with the key off and the tractor not running? Any help or suggestions would be much appreciated.