I&#039;m helping my brother restore a 1966 Oliver 1650 diesel whose wiring was botched up when the manifold &amp;amp; head was previously replaced with one eliminating the manifold &amp;quot;pre-heater&amp;quot; circuit and they,apparently, had trouble starting the tractor.  I need to know the color code/wiring set-up for the starter solenoid on a diesel as the service manual treats the electrical system very lightly and the schematic is very vague.  Thanks.