I think the summer heat (and a bad alternator) killed my battery I just replaced the alternator in my Z24 and when testing the voltage it still is not where it should be, like now is holding steady around 12.98 but it used to be around 14 last time I checked (which was a while ago) I didnt really notice the needle on the charger dropping so I think the battery is @!#$ now......just wondering if the battery is drawing off the alternator output and therefore resulting in the low voltage readings or is there something else I should look into

Sounds to me like you tested once with the car off, then again with it on...

When off you should be at 12.60 +or- 0.15 or so...

When running you should be at 14.80 +or- 0.30 or so...


You're reading my line-break, you are a loser. Lurch <3's the c**k.

checked while running at 2000 rpms and also at idle. voltage i listed was at 2000 rpm

Hi Lee

Did you check, with the engine running?:-

1. Across the Battery terminals and

2. From Batt+ve terminal on the Alternator to earth?

If 2. is 14'ish volts and

1. 12.98volts the fusible link or cable is defective.

You might check, with the engine stopped and ignition OFF that you have good continuity ie a low ohms reading between the alternator main/Batt terminal and the Positive battery terminal--if not maybe the bad fusible link?.
Another check would be to CAREFULLY check the voltage dropped between this Batt terminal and the Battery Positive terminal with the engine running.This can be done with the voltmeter +ve lead on the alternator Batt terminal and the -ve lead on the Battery +ve terminal--start with the voltmeter set to 20 volts scale and reduce this setting as required---you should only drop(read) about 0.5volt at the most with the engine running.

Having said all this I once had to change the battery after a garage broke the wire from the Alt Batt terminal to the Battery +ve terminal. The first indication of failure was the ABS light coming on as the wiring to the charge light was still intact!

Good luck

Alont