hi Floyd,
>> What I did find when I unhooked the load and ran the collector open, just with my meter connected, the transistor was either on all the way, OPTO LED off, or off all the way when the OPTO LED on.
This is what you would expect to happen, basically the collector current thru the TIP is transistor is the base current multiplied by the transistor gain.
So when you removed the low resistance solenoid and inserted the high resistance meter, the lower current thru the TIP would switch off or saturate the TIP.
Example for explanation,
IF. the base current is say 10mA and the transistor gain is 40 then the collector current would be about 0.01*40= 400mA,
with a load resistance value of 14R, the voltage drop across the load would be about 0.4 * 14 = 5,6V [ which you measured]
If now you replace the 14R load with a higher resistor value of say 30R then you would get a voltage of 0.4 * 30 = 12V.
across the load [solenoid]
In order to get the same 12V across the 14R solenoid you will have to increase the base current to about 25mA. 0.25 * 40 = 1Amp.
Its important to note, that as the collector current is increased the transistor gain will fall.
Did you design the circuit?
Eric