how can you crisp up the transformer with too little voltage?

I didn't think to use the factory dimmer with the indiglo gauges, but with the HVAC I did, only because I used the power connector for the HVAC panel which is right there anyway. No problems as of yet...but unless you give it more than 12v, I fail to see how it will fry

1999 Silver Frost SVT #609 of 2760 Quaife, lightened SVT Flywheel, SPEC stage II clutch, removed resonator, k&n drop in - various other goodies too.