{HEAD ~ Numerals} 421, 451 and 461 represent {TAIL ~ solenoids} of the change over valves 42, 45 and 46 
{ HEAD ~ Numerals } 421 , 451 and 461 represent { TAIL ~ solenoids } of the change over valves 42 , 45 and 46
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH