diy for reverse indiglo gauge

[KdMkIdd00]

i know ive seen it on this site and i cant find it with search can any one help. i have a pretty good idea how its done:
remove needles,
do i have to remember the speed and the rpms ie. 60mph is 4000rpm and do i have to have the gas just about empty.

there is a red and black wire, red goes to headlight one or 12v and black to ground correct.

now there is a chesse ass on off swicth that just looks horrible do i need this if i hook the red wire to the lights, im i going to have to press the switch on every time i want it on.,

[KdMkIdd00]

okay just wondering i found a diy, they say hook the power up to the dimmer. one said to use the constant power in the dimmer the other says to use the wire that controls the dimmer. which should i use

[danhimself]

Originally posted by KdMkIdd00
[body]
okay just wondering i found a diy, they say hook the power up to the dimmer. one said to use the constant power in the dimmer the other says to use the wire that controls the dimmer. which should i use
[/body]

well if you want to be able to control the intensity of the light in your gauge then you should connect it to your dimmer and not the constant. i guess it just depends on the kinda power you want over the light, do you want to be able to dim it or have it on at full all the time?
then again im relating this to residential circuits...which im guessing couldn't be ALL too different...theres lots of people here that could probably answer this better.
i hope i helped a little.uzzled:

[KdMkIdd00]

okay i got everything all hooked up, the only thing is that the gas gauge doesnt work any more...any input