DiscoDavis
Well-known member
Have VDO voltmeter in my last blank spot on the dash. I pulled 12v feed from the next gauge over, the water temp. Was fine for months, when it was first hooked up I found it to be a bit off on the actual voltage, so adjusted the little screw slot on the side to get it to read correctly. All fine
Since then, I ran a wire directly from the gauge, to the fuse box on the aux battery as always hot (on a 5A fuse). Same issue, was a bit off, adjusted a few times to get it roughly right again. Was kind of wanting to have it display the aux battery voltage, but also both battery voltages together as they are hooked together when vehicle runs. What is weird is that it is not accurate when running vs sitting (and vice versa).
Multimeter: Both batteries read ~13.9V @ idle, ~12.9V engine off
Gauge: after adjust, reads ~13.9V @ idle, ~13.2V engine off...
Should I be doing all adjustments with as little electrical load on the batteries as possible? IE headlamps off, gauge lights off etc. It was pretty accurate when wired to 12V feed from temp gauge, I just wanted it to be on all the time vs having to switch on the glow plugs and ign circuit just to see what battery volt was.
Doesn't need to be perfect, all I care about is knowing I have enough volt to start car, run winch, run all the halogens etc.
Since then, I ran a wire directly from the gauge, to the fuse box on the aux battery as always hot (on a 5A fuse). Same issue, was a bit off, adjusted a few times to get it roughly right again. Was kind of wanting to have it display the aux battery voltage, but also both battery voltages together as they are hooked together when vehicle runs. What is weird is that it is not accurate when running vs sitting (and vice versa).
Multimeter: Both batteries read ~13.9V @ idle, ~12.9V engine off
Gauge: after adjust, reads ~13.9V @ idle, ~13.2V engine off...
Should I be doing all adjustments with as little electrical load on the batteries as possible? IE headlamps off, gauge lights off etc. It was pretty accurate when wired to 12V feed from temp gauge, I just wanted it to be on all the time vs having to switch on the glow plugs and ign circuit just to see what battery volt was.
Doesn't need to be perfect, all I care about is knowing I have enough volt to start car, run winch, run all the halogens etc.