I didn't take pictures while in the middle of making my masterpiece of surgery 
ops: so this crappy drawing is all I have.
If I had a dremel with a cutting disk, you can see where I would have been able to cut a slot in the top of the old gauge face. I actually marked the top of the old gauge face in picture number 2. That would have allowed you to see the word VOLTS when the finished project is in the car. I think about 1/8" to 1/4" would do the trick.
I haven't done the MAD electrical wiring job yet yet, it's only about $12 to do this little project.
I used a dead alternator gauge so I didn't feel bad about mutilating the thing. The volt meter, I got from Amazon. It is the Sunpro CP8215 StyleLine Voltmeter - Black Dial
BE CAREFUL the wires in the new voltmeter are VERY VERY delicate and are easily broken.
Tools needed;
Pliers, small phillips screwdriver, small common screwdriver, tin snips or trauma shears, drill and 3/64" drillbit, and 1 beer.
To get the voltmeter out of the case;
1) Note which terminal is positive and which is negative. mark one with a sharpie or paint.
2) take some pliers, and a small screwdriver and peel the crimped collar off.
3) take the nuts off the terminals on the back and gently take the meter out.
4) take the gauge face off the meter, you will need it to test fit against the old alternator dial face to figure out where to cut.
5) place the new gauge faceplate up against the old alternator gauge face. You will see where to cut a small slit on the old gauge face to make some tabs to hold the new gauge faceplate in place.
6) once you have the two tabs made by making a small cut about 1/8" which you will fold in a little bit to hold the new faceplate in place.
7) put the new faceplate in the old gauge face and mark the screw hole centers in the old gauge face to drill.
8) use the 3/64" drillbit to make the holes for the screws that will hold the new voltmeter and faceplate in the old gauge face.
9) Put it all together and you're done.
ops: so this crappy drawing is all I have.If I had a dremel with a cutting disk, you can see where I would have been able to cut a slot in the top of the old gauge face. I actually marked the top of the old gauge face in picture number 2. That would have allowed you to see the word VOLTS when the finished project is in the car. I think about 1/8" to 1/4" would do the trick.
I haven't done the MAD electrical wiring job yet yet, it's only about $12 to do this little project.
I used a dead alternator gauge so I didn't feel bad about mutilating the thing. The volt meter, I got from Amazon. It is the Sunpro CP8215 StyleLine Voltmeter - Black Dial
BE CAREFUL the wires in the new voltmeter are VERY VERY delicate and are easily broken.
Tools needed;
Pliers, small phillips screwdriver, small common screwdriver, tin snips or trauma shears, drill and 3/64" drillbit, and 1 beer.
To get the voltmeter out of the case;
1) Note which terminal is positive and which is negative. mark one with a sharpie or paint.
2) take some pliers, and a small screwdriver and peel the crimped collar off.
3) take the nuts off the terminals on the back and gently take the meter out.
4) take the gauge face off the meter, you will need it to test fit against the old alternator dial face to figure out where to cut.
5) place the new gauge faceplate up against the old alternator gauge face. You will see where to cut a small slit on the old gauge face to make some tabs to hold the new gauge faceplate in place.
6) once you have the two tabs made by making a small cut about 1/8" which you will fold in a little bit to hold the new faceplate in place.
7) put the new faceplate in the old gauge face and mark the screw hole centers in the old gauge face to drill.
8) use the 3/64" drillbit to make the holes for the screws that will hold the new voltmeter and faceplate in the old gauge face.
9) Put it all together and you're done.
