Well! Changing to the solid state voltage regulator on my '64Dog with its completely stock 37(?) amp alternator solved the lights dimming at idle problem.

Here are some truisms:

A 120 amp alternator with a decent voltage regulator puts out exactly the number of amps the system requires.

A 120 amp alternator will put out up to its rating if you load up the system.

Throwing 120 amps at a 37 amp system loaded more than its capacity WILL cause any weak spots to become obvious, as the magic smoke escapes into the air.

Having battery voltage drop, as an instantaneous load is applied, is normal. What you see as the voltage rises to the right number is what the voltage regulator is supposed to do. As it senses system voltage dropping, it increases the field current to increase alternator output.

Most of the loads hooked to the power circuit have an instantaneous inrush current which is two to three times the operating current.

Back in the day I bought a small round ammeter device that was held against the line in question and read out amps. I can not find it now.


R.