Just slapped my battery in the trunk. I used some 1500+strand welding cable for the positive lead and the new ground. Brought the pos. lead up to an industrial two-cable lug mounted in the engine compartment, tied the negative lead to the frame in the rear, and then grounded the water pump to the frame in front. I'm pretty sure I did it right. THE QUESTION IS:
Idling in park @ 775 rpm = 13.2-13.3 v
Idling in drive @ 600-625 rpm = 11.9-12.2 v
Driving @ 35mph @ 14-1500rpm = 13.0 - 13.5 v
These numbers do not look correct to me. With a good load, AC, Defrost, lights, it will stay above 13 volts if I'm driving. At an idle it will drop to 11.9.
I have a BRAND NEW battery and I had the alternator checked this morning. NAPA tested the battery in front of me.
Please send useful information, or bullets in my direction.
I have always run the ground up to the bell housing on the tranny, along with attaching it to the frame.
Because our cars are power hungry. This has worked for me.
Do those voltage readings look right to you? I am thinking it needs to be closer to 14 volts when you are driving around. I may just be picky, but this car has TAUGHT me to be that way,
My battery is in the stock location and my voltage never gets above about 13.6 volts. Everything in my charging system is new and I am using an Optima red top battery. I think you are fine.
Erik (Fuzzy) Skarsgard
87 GN
Thanks Erik.
These numbers look fine to me.
I have my battery in my trunk.
I have a schematic of it somewhere.
Anyway, I used 1 gauge cable. The battery is grounded to the frame and the chassis in the rear of the car. In the front, I have the engine block, frame and chassis all connected to each other.
The POS battery cable goes only about 12" to a solenoid. Then, about 18 feet to the starter. This cable is only hot when starting.
I have another cable running off of the alternator that first goes to a distribution block for the fuse box, fans, ignition, etc, and then back to the battery. 200 amp fuses are on this cable in the front and rear.
I have a high amp alternator, high torque mini starter and optima deep cycle marine battery.