I'm new here, 97 Isuzu Rodeo, when it gets cold out I need to be careful with running too many accessories the alternator just can't handle it. For instance if I have on the rear defog, wipers, heater and headlights, the alternator only seems to charge at 8-some volts! My mechanic checked the alternator and says it checks out, but I suspect his meter may not put the load on the alternator that all my accessories do.
Summer, not a problem, when the weather is warm the AC and headlights don't cut the charge too much. Battery is new.
So, does anyone know an easy fix for this, short of replacing the alternator or my current method, which is to not use too many accessories at one time?