Note: Sorry, I don't know what kind of measurement is used to measure electricity in the car (i.e. amps, ohms, volts).

Whenever I start the car in the morning (cold start), the battery meter on the dash is around the 15-16, and even if I use things like the defroster, radio, windshield wipers, headlights, fog lights, and the rear defogger, I can make a whole trip without seeing the available voltage drop by maybe 1 or 2 notches, tops.

But when I drive the car at night, here's where the problem starts.

I start the car after 8-9 hours of rest and let it warm up for about 2-3 minutes, depending on the outside temperature, and I let the main and rear defoggers do their work. When I start to drive, I turn on the front and fog lights, and then I notice my voltage drop to low levels (about the 10-11 level on the dash), all the lights begin to dim, and the car's RPMs drop to about 300-400 RPM when in idle in drive. But I start regaining voltage back when I turn off the fog lights, rear defogger, and main defroster, I only gain back about 1 or 2 notches.

Is this a problem? Or is this nothing to be worried about? If so, what measures can I take to improve voltage management; new plugs? Better spark plug wires?

Car's description is in the sig, and I have a 720 CCA ProStart NASCAR battery.

TIA.

 

Have your alternator checked at a local auto store. They normally do it for free.

 

I have an 87 bird that had the same symptoms. Replacing the headlight modulator helped the situation with the lights pulling the car way down. Also try tightening your alternator belt. Take you alternator off the car and have it tested at the local auto parts store. Some voltage drop is normal, but excessive particularly if the car is dying is a good indication that the alternator is going bad.