Hello guys,
I had a problem with the headlights dimming slightly in pace with the turn signal and a significant dimming when I turn on the blower fan. I discovered the cause by accident when I brought in a wire from battery + terminal inside the passenger compartment through the window, so I can monitor the battery voltage while the car is running. I used the chasis for ground, then I realized I was getting 1V lower between B+ and chasis relative to directly across the battery with everything turned off.
So I popped the hood and there was a potential difference of 1.1V between the engine block/rest of chasis and battery negative post. I figured it was a poor ground connection. Removed the grounding jumper, sanded both contact surfaces with Dremel, applied WD-40 to prevent future corrosion and remade the connection. Now, I see about 1/1000th of a volt between the block and battery terminal.
With this corrected, I am reading 13.7 to 13.9V and ocassionally jumping to 14.0V. Does this sound right? (measurements taken with a 0.5% DCVM). The headlights doesn't flicker, but the dome light do flicker with the pace of turn signal.
Can you guys advise me of other high curent electrical connections I should check? I'd like to know where to probe around and what readings to expect. (i.e. between alternator B+ and battery pos terminal, about xxx V under heavy load)