Some fairy from a shitty forum told me that when you ground your amp you will never see the full 14.4v unless you run a line all the way back to the battery. Here is what I found in my test....that is utter BS //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif
Originally Posted by cptomes
You've just quoted a perfect reason to run a dedicated ground. A fully charged battery with no charging current going into it and light ( like a dome light, no key in the ignition) load should show 13.2V , if the car is running fast enough to power the car's load and charge the battery it should read 14.4V. This is determined by the chemistry of lead-acid cells.
If you're showing less than 14.4V when the car is running above the RPM where the alternator puts out enough current to have the voltage regulator dump excess to ground, then you have a problem.
I have NEVER seen any of my cars show 14.4 when I tried to ground using various chassis locations. Spot-welded thin guage steel is a really crappy conductor compared to even an 8ga copper cable.
My reply.......
Hey bro I tested my truck and you are.........wait for it........wrong........
Test, DMM set on DC
Car off
At battery posts 12.7v
at amp 12.7v
car at idle
battery 14.2v
at amp 14.2v
RPM @1k ( full charge)
battery 14.4v
amp 14.4v
I will gladly take pics if you like...I have dial up so it will take forever to upload.
Now some food for thought...batteries are made of 6 2.1 volt cells, thus 12.6 volts, and the 13-14.4v... that's just the way they are different brand auto makers set their alternators to produce different volts, yes some people get 14.4V or so but a lot of cars run closer to 13.6-13.9
If you get 14.4 at the battery but less at your amp, you need to sand better around the ground and or find another place. Seat and seatblets seem to be a good place.
