Hello everybody im super new to this website and barely figured out how to post a thread. So I need some help please like a step by step guide on how to install an aftermarket RMP gauge on my toyota pickup 1990 3vze. Like the proper easy way. I'm fairly new to messing with wires.

 

Do you already have the gauge and mounting hardware, or is your question regarding selection of an appropriate gauge plus hookup?

Generally speaking installing a tachometer is straightforward. There will be 4 wires to hookup.

1) ground (attaches to the body/frame) - find a bolt and nut with a solid metal connection under the dash.
2) ignition power - a 12 volt wire that is energized then the truck key is in the "ON" position. Usually this is easiest to tap into a wire from the fuse box under the dash.
3) illumination - a 12 volt wire that is energized when you turn the parking lights (and dash lights) on. Again, you might be able to tap into a wire from the fuse box.
4) tach wire - this will typically be connected directly to the negative terminal of the coil, or possibly the green connector for the ignition module.

If you are completely new to wire, with no past experience making connections or tapping into wires, you'll benefit from some basic education on how to make splices and such. There is an abundant amount of utube videos that can help you learn the basics. If you know how to splice and tap wires, then doing this in a vehicle is the same basic process. But, remember anything exposed to the elements (in the engine compartment) will serve you better as a solid water tight connection (not a 3M quick splice).

You will also benefit from getting your hands on a wiring diagram for your truck. I'm not sure if a Haynes manual will include this info, but you can check. Also making a request to the group could mean finding a pdf of said diagram in your email.