Anthonyb

My battery meter normally reads halfway between the first white line and the 14. First off is this normal or is it low? Secondly today was pretty warm out so I kicked on the air and turned up the fan, when I did this the meter visibly dropped to the first white line. Turn the fan to low and it went back up. Is this just the signs of a bad battery or do I have some other problem?

mike albo

thats normal for the accesorys to draw that much

Anthonyb

Cool thanks. I'm a bit surprised it draws that much but this is my first jeep and I'm quickly learning all the little details. What should the meter normally read? 14 or just below? Definitely don't know anything about electrical so that may be a stupid question!

5-90

1) Blower fans are notoriously high-draw.

2) Alternators cannot generate full output when idling, it's usually closer to 40%. This is just the way things work, and that's why load-testing a unit requires spinning the pully at about 3000-3500rpm (which would be 1200-1300 at the crankshaft, in most cases.)

3) The IP voltmeter is a notorious liar. Always verify any suspect readings using a separate test voltmeter (digital multimeter, analogue multimeter, ...) at the battery terminals underhood.

Acceptable voltage readings at the battery, engine OFF, fall between 12.0-12.9VDC (12.6VDC preferred.)

Acceptable voltage readings at the battery, engine RUNNING, run 13.0-14.5VDC (as long as the alternator isn't overloaded.

If the IP meter is overly far off, I usually end up checking the readings and making a new set of marks using a grease pencil on the IP window. I'll eventually replace most of the gages with aircraft gages anyhow - I like the look of them...

Anthonyb

Great info, trhanks!