I have the Arc 110 welder.
Looks like it uses the same guage for showing the setting.
Looks like it just like one of the old radio indicators.
Should be easy to take it apart and fix it if it don't work.
If the sticker is gone showing the settings
just take a marker and draw them back on using the chart.

Pooh Bear

Here is a link that might be useful: Arc 180

Craig,

I'd just do some practice welds with it. Once you get a good weld on say, 1/4 inch stock, mark that as 125 amps and work from there. That will be approximate. Do the same for 1/8 inch steel. That will be about 90-100 amps. If the heat is too light, it won't penetrate and it will be hard to hold an arc. If it's too hot, it will undercut and burn your work.

My mig welder has three rocker switches and a wire feed speed control. No amps indicated, I just set them where I get good welds and remember those settings.

Another point with a stick welder, you need more amps with bigger rod, so keep that in mind. If you use a 1/8 rod on 1/4 inch stock, and it welds good, you will need to increase heat a bit with a 3/16 rod.

GG

Gooseberry is right. The amp selectors on most stick welders are just to get in the area of amps desired. After that a lot of variables come into play, such as rod dia,rod type(6011,6013,7018),thickness of metal being welded,position(flat,horiz,vertical,or overhead), and how close you hold the arc between rod and metal. It just takes experience to determine where to set the amps.
Hope this helps,
Mike

Measure the output voltage at the various settings and calculate your way backwards.