Had a bit of a blonde moment with the Alternator, I was thinking too much, 12v+ then internal rectifier switches to ground when the Alternator starts to charge. Same as toyota

Added Note

The original toyota ECU runs a canbus (TX/RX, toyota call it MPX1/MPX2) to the combination unit, this feeds ok commands back and forth, I've found that simple things like the handbrake light won't go off unless the engine ECU detects the alternator charge light function, Basically I need to have the Toyota ecu connected up, I've also checked signal calibrations for my VEMS tachometer output (12+ pulled to ground to give pulse). Now reading as desired, I'll calibrate the tacho via the VEMS when it's dyno'd.

I fabricated a fuel tank a while back using a vw passat fuel pump and sender unit, unfortunately an earlier toyota fuel sender test ended up in flames, so I didn't have a reference for the correct type of resistive signal back to the gauge (combination meter) I tried everything to get a reading and turn off the low level light, but to no avail.

A recent purchase from ebay for a toyota complete pump/sender unit has now enabled me to get the gauge working, I've got to encorporate the toyota fuel sender into the VW package, thankfully not too much hassle.
My original reason for the post was to ask about the slow movement of the gauge, I was checking out all voltages and ohm readings to and from the gauge, all parameters seemed to conform to the toyota specs but I couldn't get the gauge to move, I went into the house to look at another dial set and left the ignition on by mistake, 3/4hr later I came back into the workshop and the gauge was reading full! so it's fine

My Question is: Are these gauges dampened this much, I realise the integrated circuit controls the voltage to the gauge, just need to be sure they are really slow to move, I approximate about 20mins empty to full, I haven't checked if the combination meter speeds up it's rate of voltage change if the engine's running.
cheers
Darren