Mono valve on a 126 Voltage reading?

[Bens lover]

What is the normal voltage I should read on a 1983 126 female connection of the Mono Valve.
This is the reading I'm getting.
On one side I get 0.03 volts,and the other is 12.07 volts this is with the engine running for about 5 minutes.
Is this right?
Because this is the issue I have.When the engine is cold and I start the car it will take a little while before i get heat.After the engine has warmed up and I start driving,then i get cold air.So what i have tried doing is while I drive I turn the temperature knob to its coldest point,and the a/c switches on with cold air.Then i turn the knob to the warmest setting and I get luck warm air at best.I have to come to a dead stop with the car,engine still running and then I repeat the procedure again,this time the air gets very warm short of hot.
Just a few moments ago I went to dismantle the front dash to have access to the back of the heater control and to check the pods that are there.They both seem to work fine.The bottom door opens to let heat at your feet and all,so now I'm a bit confused???