Pierberg heater problem

Afternoon folks - happy bank holiday !!

So cabby has been released from its winter sleep (late I know) and after a Pierberg half carb swap (broken float hinge casting), I set about tidying some wiring up around the carb ..

Found some weird goings on about the heater …

Easier if I bullet them …

- the single wire coming off the heater rings to earth … does this mean it's broken down inside ??

- the wire going to it from the harness was actually two twisted together , when I tested these one is earth and one is switch live …  "a" is returning 11.5 volts when ignition on and the other "b" is indeed ringing to earth … I'm confused …

- I assume the "a" should be the heater wire &  connect the "b" to the carb earth maybe ? (There's already a carb earth to rocket also)..

Car is running fine as is but I'd like to resolve this , so may help appreciated …

God Bless Ya

Ok after a bit of googling this afternoon it seems the heater wire grounding is a common problem , maybe not internally but the wires as they fray and exit the unit itself , I'll remove completely to test fully ..

A question I didn't ask above though … if I use the current loom wire it would seem it's live as soon as ignition is on … so this heater stays on all the time while engine is running regardless of carb temp ??  Is that right ??

In order to add some research to this for anyone else with similar queries..
Found this extract below at this link ..

https://vwt25.blog/2016/09/15/pierburg-2e3-rebuild-and-adjustments/

"Heater
The next part i'm going to fit is the 12V heater, it looks like this. That fits to this part of the carb here just under the idle cut off valve. What that does is heats up this section of the carb making sure it runs OK in cold weather conditions. It's connected to the thermally switched 12V system as well as the small heater that's in the manifold. The hedgehog looking thing. These two things, once the coolant system gets up to a certain temperature, these two things switch off because they're no longer needed as the carb is up to a certain temperature already. That just fits here and is screwed in place with one screw. That's in position now."

So where i was questioning if it was perm live , seems its not, although i will now test this when upto temp.

Still have a none working heater though, even after strip down and rewire/solder..
Re-assembled but it does not heat up..

Anyone aware of a rebuild guide for this just in case im missing something ?