I dont have a voltmeter, and i need to find a wire that is 12V Switched Power to hook up my rpm switch. if someone can help me find a 12V Switched Power wire under the hood of my 1991 crx si, i would gladly appreciate it.

 

On your drivers side shock tower, there should be a grey plug. It has a bunch of yellow/black wires going into it, but there is a cap on the other side of the plastic plug. That is a 12V power distribution block, you should be able to tap any of those wires.

 

u dont need no stinkin volt meter... speaker wire and an LED would be ideal otherwise pull the bulb out of your dome light.... flick key on and off and watch for light...
only one thing.. make sure you are NOT probing a computer's wiring...

 

use your fuse box its much safer your ACC on the fuse box are alternator fuse(14); radio (8); starter signal (2)