Originally Posted by afearlesshunter
I installed a new subwoofer amplifier in my new to me 2003 Wj with the 4.7l v8 and I noticed the amp was getting hot quickly. Tonight I checked my voltage (With the jeep running) and it read 29.2 volts.. What would cause this? is this normal?
You have a major problem.
However, is it a major problem with your charging system (29.2VDC is FAR too high for a 12V system!) or with the meter you used to check it?
Verify it with a second DMM.
Nominal voltage for automotive systems is 12.0VDC. Typical battery voltage is 12.4-13.0VDC, typical running system voltage is slightly higher (12.8-14.0VDC.) More than 14.0VDC is a problem, and engine running system voltage should always
be higher than resting battery voltage, typically by at least 0.25V.
You can find a writeup I've posted on testing primary electrical components here, but make sure your DMM is properly calibrated and reading correctly first...