resistor is cutting your power/voltage down,that is what they do
why did you put a resistor in there??That will LIMIT the voltage[getit:RESISTOR].....Take the resistor out to begin with,and my best guess is that you have too much voltage being pulled from that one circuit,making the last thing in line[the gauge]dimmer than the rest....Do you have electronics experience??IMHO it's one of the hardest things to learn,I know when I began to repair electronics I had to learn the resistor color codes,what a diode was for,and when these certain parts were needed etc......