Usually when you buy an used DSM you're going to find leftovers of there tracks and
"Mods" Like Narrowband, Boost gauge, 5" Tach, Ricer Taillights
Here is a pic of what not how to hook up gauges.
These are easy fixes and most beginners who see this and tend to freak thinking its going to blow. Calm down. The biggest skill you need to repair these issues is Patience. I spent near 8 hours re-wiring three gauges so don't think you're going to do this in a quick minute.
1st thing you will need is the necessities of Electrical work, I bought mine brand new so I know they will work and being from Walmart I paid $20 for everything you see.
The first thing I did is set up my external fuses for all my gauges. This helps to keep each one at a safe Current and Voltage. Also if one breaks not all will be affected.
Now with one side done with positive I decided to do the ground wire. Pretty easy to do, I tend to take one step farther so I sodered onto the terminal making sure it will not slip or rip out.
Going back into the car I notice the former owners used the un-used locations on the kick panel fuse box. I was impressive they did that considering what they've done everywhere else. Make sure you read the Panel and double check that you are using open locations. I used Male insert connections that going into locations as this, No pics now but later I will.
Here is a pic of the kick panel fuse box
Now that you know where everything is going you can remove the unnecessary wiring that is hazardous and rewire they way it should be done.
This is my finished Project of my new Gauges
Fixed wiring. All smooth and straight. Notice the wiring to the Boost gauge.
The fuse panel is rotated to teh right so the power pin is on the bottom or on the right.
The wire i'm holding up is the Open location that is connected straight to the Battery. Manual Switch Idea..
All credit for this writeup goes to: n0rthendtr00per