ammeter question

[William F.]

Prior to today my ammeter always went way to discharge side at idle and stayed about center or slight charge at cruise speed with no accessories on. Today after getting it back from some AC work(car was run at idle for some time), needle stays 3/4 way to charge at cruise and stays near center even at idle. Continued to do same even after several miles driving. Checked voltage (momemtarily) from red alternator post to ground and got about 13.5V which seems ok.With car off, batt. reads 12.6V. Just screwy ammeter or something else-don't know how to explain the definite change in reading? Don't want to blow up battery.Check something else or forgetaboutit?
Thanks

[Francis F.]

Re: ammeter question

William,
you mentioned some a/c work being done,just a guess but coulb be the elect clutch could be hanging up..staying on ,causing alt.to charge more to make up for this current draw. mabey take back & talk ti\o a/c guy.
Francis (nice last name )

[Jack H.]

Re: ammeter question

Position of the pointer needle varies based on the exact state of battery charge AND the current system drain on the battery.

With a potential of 13.5 VDC across the battery, you're nowhere near the point of over-stressing your battery. A 'typical' charge condition lies in the 13.8-14.2 VDC range.

SWEAT it when you see the ammeter PEGGED and battery voltage reads 15 VDC or higher!

You may simply be seeing the result of your battery having been depleted while the car was in the shop, an insufficient amount of driving/charging time thereafter AND you running the A/C putting the load of both the compressor clutch and the heater/blower fan on the battery...