First of all I believe that there is an orange wire in the harness at the base of the pillar for the dimmer. For Key on power, on my gauges I used an Add a circuit fuse replacement which holds 2 fuses one for the fuse in the fuseblock that you are replacing, and one for the circuit that you are adding. The radio fuse is an ignition on source, and by using add a circuit you do not jeapordize the integrity of the radio power in any way (because it still has its own fuse) The volts gauge needs to be an ignition on source also. I'll see if I can get some pics of my fuse box with the add a circuits in it. I got them at pep boys they were something like $6.99 ea. I'll post a pic of where I have my boost gauge connected in. You need to be sure you get a port with vacum as well as boost.
Alan [}
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