Hot Rods What is it? Fomoco Tool Part ???

What is this gauge use for. Thanks for all help. Peace

 

Thermometer that clips on voltage regulator cover.
http://restorecarsclassifieds.com/wiki/show_pdf.pdf?n=9880

 

read the factory shop manual for a generator equipped car, you'll see that temperature is important when adjusting the voltage regulator.

 

Adjusting a regulator was something most guys would never attempt. I learned while working the battery line at Sears in the 60's. After making a spring adjustment or cleaning the points the cover was ALWAYS set back on during the testing. When they started putting rivets on the covers most lost interest.

 

HAMBers to the rescue again. The HAMB is like a Wikipedia for vintage cars!

 

Its for checking generator output. We had one in a service station I worked at when I was a kid.