My charging system issue

WOO HOO i have my own alternator thread
NAh just a story, no questions really. I just want to spread my experience.
My voltage guage on the dash has been indicating about 10V for a couple weeks ...I also notice a lot of dimming when i turn on something with a high draw....( Heater blower, headlights, microwave transmitter, photon cannon)
but its only an initial drop, adn lasts mabye a half second.
I figgure my alternator is getting towards dead due to the low V on the meter.
I put my trusty Fluke DMM on the battery terminals with engine shut off, and nothing on.ITs the higher side of 12VDC, allmost 13V. I turn the lights on, still 12V and the lights r bright. Good to go. that, plus a healthy start every time leads to a good battery to myself.
I started the engine and the measurements are between 13 and 14 VDC. I dont see a problem there, even with a high draw on it, its a good Voltage. I suppose my meter is hurtin or i have a bad ground somewhere.
Thought i would share that its not allways best to run out and buy a battery or expensive alternator before looking for other culprits.
Anyone ever had a dash meter just be plain wrong?....Okay, i lied i did have a question huh.
Well keep on movin on...and get a coat for crien out loud, its cold!!!!!!Even south of Houston. were talkin allmost freezing !!! thats cold for us down here...

Ironically, this past weekend I was on a 3.5 hour trip in my 76 firebird, and realized my headlights dimming REAL bad when braking, but only in drive, ironically enough.. figured alternator was bad, called, priced it, then decided to pull my neg terminal, ran it for 5 mins or so, straight alternator, and no probs....

So now im on to chasing gremlines too...

My dash gage runs about 2.5 volts low.
Freezing in Texas and California over fifty today, flowers are blooming and sunny in Germany (about the same latitude as the Canadian border). Maybe it has nothing to do with global warming and the poles are just moving around.
Clean grounds are important, might want to check the one behind the window washer tank, a lot of people forget that one. I added a ground from the battery negative to the front clip and another from the alternator to the battery negative and another from the dipstick holder to the firewall. Seemed to help.
When it's cold out. My gage will go up for the first half hour of driving or so, then settle back down to the normal spot. I always figured the system was working a little harder to fill the battery back up.

I had the same problem; lights would dim and alt gauge would swing heavy to the dark side of the force.

I thought it might be the alternator, since the Battery is brand new. Then, when it got really cold, my serpentine belt would squeal like a pig and I was suddenly afraid that the alt was about to seize!

Turns out it was just a loose belt. Turned a few wrenches, said some prayers, and voila! All better.

I hope your problem is as easy a fix.

XJPhoenix said:

I had the same problem; lights would dim and alt gauge would swing heavy to the dark side of the force.

I thought it might be the alternator, since the Battery is brand new. Then, when it got really cold, my serpentine belt would squeal like a pig and I was suddenly afraid that the alt was about to seize!

Turns out it was just a loose belt. Turned a few wrenches, said some prayers, and voila! All better.

I hope your problem is as easy a fix.

Click to expand...

My jeep is doing this now also and I just got a new battery to see if it would fix it. Mine only squeals if I have a lot of stuff running. My belt seems tight and I had autozone check my alternator and under a load at 2k RPM's it was putting out nothing so I am getting a new alternator and gatorback belt.

klennop said:

My jeep is doing this now also and I just got a new battery to see if it would fix it. Mine only squeals if I have a lot of stuff running. My belt seems tight and I had autozone check my alternator and under a load at 2k RPM's it was putting out nothing so I am getting a new alternator and gatorback belt.

Click to expand...

Brutal!

How could the Jeep run? Must have been draining the battery...

Are you going with a stock alternator? Or going with a higher output one?

The dash voltmeter is a notorious liar, especially on the older ones, and one of the things that will make it dip way down is the heater fan. For some reason the shared circuitry there will make the meter go way down if you turn the fan on high. But a quick reading at the battery confirms that it's not really drawing more than the headlights. I've gotten used to ignoring the reading when using the fan on high. This seems to have been cured on my 99, but both the 87 and the 95 have this issue.