Folks, we have upgraded the alternator in my C 20. We have traded the SI 12 for a newer CS 130d.

We are getting sporadic charging, as verified with a VOM at the battery with the engine running.

Trying to figure out where the resistance is in the excitation line, since my truck has the gauges. In the trucks with warning lights, the light is the resistance. How is the same resistance provided with gauges ?

Any guidance ? GM manual stops at the bulkhead, and any other reference I have examined is generally generic in nature.

Thanks

HammerWerf