i have a 2005 300 hemi c 5.7, an my voltage gauge reads 14.1V driving or when started soon as i turn it off reads, 12.4 then quickly drops to 12.1, 12V what's the normal it should stay at an for how long?
Welcome to the forum. All 3 of my Hemi's will usually run about 14.5-14.7 right after start up with a cold engine, and fairly quickly lower down to about 14.1-14.5, depending on the accessory load that is on at the time. If any of the vehicles have been sitting for several days or more, I've seen momentary initial charge voltages as high as 15.2. At idle they'll sometimes dip below 14 momentarily, again, depending on the load. If yours is dropping to low right after shutoff, you may want to get your battery tested at someplace that has a quality battery tester. If you have access to a battery load tester and conductance tester, you can probably check it yourself. For the load test (checks battery's ability to support a load) you should start with a fully charged battery (and charge it again after the test) but the conductance tester (checks battery's ability to produce current) the battery does not need to be fully charged,....just be sure all load is off and wait a minute or so after shutting off the engine to remove any surface charge. You'd probably want to do the conductance test first. Also, if you're not aware, our computerized vehicles are very sensitive to battery condition and, if the voltage is too low and/or unstable, you may start getting all kinds of weird symptoms and sometimes malfunction indications of components.