Altenator in my 1994 chevy suburban k1500.

There's no ammeter. unless you have added electrical equipment. Voltage drop is always voltage lost to heat. Voltage drops are the result of passing thru a conductor with a resistance. Air gap, looseness, internally corroded, coated with an insulative substance, dirt, too many washers, non conductive parts, cheese, crackers, what have you ?

Connect a new wire of your own between the battery and the output on the back of the alternator, full field it. does the voltage increase ?

have you blown fuses, fusible links, inline fuses ?

Is the alternator plug ok? connector is not at fault for the wires that plug in? Did you disconnect anything else and forget perhaps???

Thanks Dannyl. You gave me a lot to think about. Will start checking all that you suggested.

There is something wrong with the wire or connection between the alternator and the battery

Yea. I came to the same conclusion. Even when my GM code scanner showed no problem. I hate trying to trace down electrical problems. Done it in the past though. Guess I'll have to do it again. My thanks to all for your advice.

If you haven’t found out what it is change your fuse for gauges