Changed that too, it controls the ISV. It used to work thats the annoying thing I think it stopped when I changed my bulbs for LEDs.
I have changed allsorts matey
All vac hoses,
all temp senders,
Clocks,
ECU, Ignition amplifier,
Voltage Regulator in clocks,
Vac unit in clocks,
Speedo Cable,
Oil pressure sender,
Oil temp sender,
my last ditch attempt is to change the LED's back to bulbs and the stalks and see if that cures it, can't see why it would but you never know!