Setting shift light?

[Black4VPower]

This is going to be a silly question but my 91 Notchback has a shift light attached to the dash. How do I set the light to go off at the desired RPM? When I start the car it lights up real quick but I have know idea if it is even set to go off. When I free rev the engine to the upper RPMs it doesn't go off, I shift at 4800 RPMs according to my Autometer tachometer because that's where it noses over. All the gauges in the cluster have been changed out to Auotometer gauges. I have done a search and I cant find any info. Thanks for any help.

 

[crfrider16]

Well, first thing first. What kind of light is it? Part #?

 

[Black4VPower]

I am not sure of the brand or part #, It was in the car when I bought. It just says "SHIFTLIGHT" on the side. It looks like the basic one that has been around for years with the yellow cap over the light.

 

[crfrider16]

Can you post a pic of it? The older Autometer shift lights had actual "pills" that you plugged into them for the rpm that you wanted to set it at.

 

[Black4VPower]

Here is a few pictures of the shift light.