12 Volt electric choke current - please explain!

[trevbeadle]

If I measure the voltage at the wire connector to the electric choke when it is not connected, it reads 12v ignition on. If I connect the wire and then measure the voltage at the choke male connector it's attached to, I only get 5.2 volts! If I take another ignition source of 12 volts from under the hood and do the same, there is only minimal drop! I understand that the choke is pulling current when connected but why the different reading? Does anyone know why?
I think the 12 volt choke supply comes from or via the CCC system on this car (1980 Californian) so is it to do with less amperage from the CCC than the battery? The choke does seem reluctant to open the choke butterfly on 5.2 volts.

 

[Oneball]

The choke will only open slowly it’s bimetallic and works on heat.

 

[trevbeadle]

I know that Oneball, my query is the different voltages I’m reading

 

[Oneball]

Looking at the wiring diagram I think you may be right and that it seems a little weird. Is your choke light on? Looks like the 12v to the choke is switched via a relay so the control comes from the ecu but the power itself doesn’t.

Maybe the relay??

 

[trevbeadle]

The choke light comes on but goes out as soon as I start the car