Pass lab meter

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That's as far as it goes. Rest is pop rivet
 
is there something (some funny electronics) contained in that little box behind those M4 screws?

what you did open is meter mech. itself and we aren't interested in that , but in fact is there anything between contact screws ( two M4) and meter coil itself

have you any Rdc reading at these screws?

if they're directly at coil , when you try to measure Rdc , needle will move
 
check Rdc with ohmmeter

if no other way ( you can't read Rdc of coil itself) , just cut those wires (yellow and red) furthest possible , drill small hole at back of instrument and route them out

solder some extension wires on them and you have your instrument ready to connect to whatever you want
 
standing current

Iq is shortie for Quiescent Current

if you need that ( and that's best for monitoring) , I need to know what you're building in that case , so I can tell you how to make it

in case that you already know how to connect it , even better 🙂

btw. you didn't tell - did you succeeded in routing instrument wires out?
 
remove everything shown inside (resistor , cap , diode_

solder coil wires to output terminals/screws and close it

make test circuit by attached sketch , start with maximum value on trimpot, fiddle with trimpot to get full tilt of needle , then write down current and voltage

after that we have all data needed to implement it anywhere
 

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