I can’t seem to find an answer to this anywhere I go. I want to wire up all my aftermarket gauges independently of any factory wire behind the dash. This means running a wire from the battery to a switch then to the gauges. What I don’t know is that I’m pretty sure I need to run a relay. Is this true? If it is, would i put the switch on the “ignition” terminal on the relay and have it come from the battery also? I’ve googled it but can’t find anything specific as to what I want to do. I schematic would be a big, big help if anyone can draw one up for me. Oh and the reason why I want this is because I have 6-7 aftermarket gauges basically running on 1 ignition wire and 2 illumination wires behind the dash. Zack
you won’t need a relay unless the current draw on your gages is more than your switch is rated at.
If you are pulling directly from the battery instead of the fuse box, make sure you run a fuse inline.
If you do use a relay, here is a quicky schematic google found that would work. Just substitute your gages in for the fog lights, and run the ‘12V Power’ lines through fuses to your battery.
gauges do not draw much juice. you can find an ignition wire “hot” in a lot of fuse boxes. check to see if an open slot exist in the car you are working on.