"02996ttx50

agree. 13v is fine if under load. 13.8 no load is the most you should see on the gauge.

if you question the integrity of the battery? its a 150$ wear item lol.

993GT

batteries are super easy, anything H5 up to H8 fits, H8 , may require a nut welded to the battery tray's final hole if not already equipped (H7 is a guarantee fit and still tons of CCA and R.C.)

spooltime

Don't forget to do voltage drop tests on both the alternator to starter cable and the engine ground cable. These cables are known to develop excessive resistance due to corrosion/ heat / age. If the cable is going bad, you'll never get the voltage the system is supposed to deliver.

jhall

Can someone tell me where the engine to body ground strap is located? Maybe a picture or two?

Carlo_Carrera

Passenger side, just behind the rear fender liner.

jhall

Can I see it if I crawl under from the back?

Carlo_Carrera

Sure, just get under there with a flashlight.

32krazy!

its much easier to remove the pass wheel and fender liner to access the ground cable

jhall

Okay, I replaced the battery with a Bosch H7 AGM. Not surprisingly the charge voltage is still low. Also, printed on the battery is says Recommended Charging Voltage 14.4v +/- .2v.

So I'm at least a volt below the recommended charging voltage. Is the consensus to ignore it and drive on?

Oh, I looked and still couldn't find the engine to body ground strap. I'm pretty sure it isn't the issue because I get the same readings when I check the voltage directly on the engine.

"02996ttx50

VR - check
battery - check

alternators all that's left no? exactly why i dont mess with only the VR. now you need to r&r the alternator. what else could it be. GL with it.

s65e90

There's nothing wrong with your car. Leave it alone. No way to see a proper 14 volts into the bay as the voltage drop from the FRONT mounted battery to the engine loses a little. 12.xx up to mid 13s is fine for voltage.

Third-Reef

I agree that this is normal. My car is the same. However something to look at: Cold start with your lights and AC on and the car running for 4-5 min, feel the cable from the alternator where it connects with the starter cable there at the terminal block in the engine bay (under the little cover). My cable runs hot, like heated by the amps running through it, quite noticeable to the touch. I have thought that if I upgraded that cable to a larger gauge it might read closer to 14V than the 13V i normally see. I have not taken the time to measure the voltage drop on that cable, but that would be definitive.

pancing

Your car is fine, mine sits at 14v if my ac is off I turn it on and its at 13v.

Drive it as often as you can and enjoy it!
Its not a c5 z06 with loads of electrical issues.

autobonrun

Rather than discussing actual charging voltage I’ll say a healthy 6 cell battery has 2.1v per cell for a total of 12.6v. Anything over 12.6v when running and it is charging. How much over 12.6v determines how fast.

Usually batteries that have been sitting start out less than 12.6v. Much over 14v when running and it is overcharging. That can be just as bad for battery health.

Kevinmacd

In order for a lead acid battery to become fully charged, of 12.6 volts the charging system needs to produce 13.7v - 14.6v. Use a volt meter on the battery terminals to determine the charging voltage. The gauge in the car may be a little off. My car with no AC an no full load shows 13.9 to 14volts. Full load it drops to 13.8. Before replacing the Voltage regulator, It would show about 13 volts full load and never showed 13.8volts.