Batt. light mystery.

[Smokey Eddy]

batt holds 13.3 volts.
alt charges at 14.3 volts.

when the car is turned off the batter gradually drops 0.1 volts every second and stops at 13.3 (give or take a couple tenths).

My battery light flickers and is sometimes solid while driving and this is all the time. Any thoughts?

I tried playing with the rpm while monitoring the voltage at the battery terminals and rpm made no difference.
I am under the impression that these voltages are adequate.

I was planning on running a secondary battery in the trunk.

I'm totally stumped.

[clbanman]

If your alternator consistently charges at 14.3 and your battery holds 13.3 there is nothing wrong with either.  You have something wrong in the light circuitry.

[Vincent Waldon]

batt holds 13.3 volts.
alt charges at 14.3 volts.

when the car is turned off the batter gradually drops 0.1 volts every second and stops at 13.3 (give or take a couple tenths).

My battery light flickers and is sometimes solid while driving and this is all the time. Any thoughts?

I tried playing with the rpm while monitoring the voltage at the battery terminals and rpm made no difference.
I am under the impression that these voltages are adequate.

I was planning on running a secondary battery in the trunk.

I'm totally stumped.

Your battery sounds fine.. at least from a voltage perspective.   Batteries are partly capacitors and so it's normal for it to slowly drop in voltage from the charging voltage (14.x) to the charged voltage (13.x) soon after the engine is switched off.

On our cars a flickering or dimly glowing alternator light is pretty common.  When it's associated with normal charging voltages it almost always results from a increased resistance in the ground path between the alternator and the cluster... the additional resistance allows a small voltage to develop, which drives the BAT light slightly.

The fix is to check the ground path carefully... clean metal-to-metal contact wherever the alternator bolts to the engine block, good grounds from the tranny to the chassis, and chassis to cluster (star ground under the dash).  You may find directly grounding the alternator case helps.

In terms of a solid light... that's a different issue and almost always means that the alternator is in distress... are you able to measure the output voltage while you're on the road and when the light comes on?

[Smokey Eddy]

Thanks for the prompt replies!
Okay, i'll check the grounds. I have added an additional ground though and replaced the old grounds with very large ones. The terminals on my battery are both lead now.

An important symptom is that the light goes out with my high beams on.

"If your alternator consistently charges at 14.3 and your battery holds 13.3 there is nothing wrong with either.  You have something wrong in the light circuitry."

[maxfax]

One of my past rabbits did just about the same thing..  Turned out to be a bad ground to the cluster itself..  I cleaned the plug and terminals on that and it fixed it right up... The gauges worked better too!

[catlin_cava]

I'm having the battery light constante on my gasser right now, battery is fully charges and altenator is new...

[Smokey Eddy]

hey yeah my temp gauge just stopped working. I'm going to dig out that ground.
fixed my gauge. it was unrelated.

where is this ground?? I had a poke about with the cover off under the steering wheel. Que?!¿

[maxfax]

I pulled my cluster out, it was the actual connector into the cluster that was giving me problems.. 

[Smokey Eddy]

I pulled my cluster out, it was the actual connector into the cluster that was giving me problems.. 

and the fix was? replacing the whole pig tail?

[maxfax]

I cleaned the contacts on both the pigtail and the cluster with some electrical cleaner and crokus cloth. then bent the little contacts in the pigtail so that they pressed against the contacts in the cluster a bit tighter...

[Smokey Eddy]

PURE GENIUS!