As you can see in the vid, with signaling, the battery voltage fluctuates. That was with the AC on and fog lights on. Then, when I put in Drive, the signal indicator starts flashing slower, and battery voltage drops.

1993 LT1

 

Look at your digital. could just be a bad connection or ground.

 

If you have a multimeter you can test the DC volts on the back of the alt.

 

I do have one. How would I test that? I just did the battery, and it's at 12.54 volts. Battery connections are tight, no corrosion on them.

 

Start it up(mind the belt), put the red lead on the pos post on the rear of the alt(big red wire covered by rubber boot) and grd the other. It should read bout 13-14 at idle and no more than 14.8 with some rpm.

For example my old alt on my 77 was 12's at idle with under drive pulleys but 14.7 with just a little rpm, new one is 13's at idle n same at rpm. But that is a carb car and ecm are little more picky on idle volts I've herd.

I'm sure others will chime in or you can find some vids on youtube, GL

 

Make sure your belt is not loose or worn.

 

It's not loose or worn. I saw a vid on YouTube of Chrisfix and I'll do his alternator test tomorrow.

 

The alternator is barely functional at idle. Some alternators are better than others in this regard. It's normal to see fluctuations in the brightness of the dash at idle.

 

I agree, I've seen it mostly on Chevy's to. But when I put it in drive, it started to signal slow, you can even hear it in the video. I'll get to diagnosing it in a bit.

 

I solved my idle charging issues by swapping to a cs144 alternator I took off my 97 firebird.

I thought the lt1 cars had the cs144 like my firebird has since its an lt1 car too but maybe not. I do know the cs144 charges great at idle and the cs130 that is normally on an 86 or 87 like mine doesn't.

Just went and looked and it seems that 92 on up should have a CS144 so if its not charging at idle it isn't because the alternator is supposed to have some inherent problem with charging its either a loose connection or bad alternator. Because a properly working CS144 will charge just fine at idle in gear with headlights a/c etc on. True charging beast.

 

Forgot to mention my C3&C4 charged better with a new larger main ground cable.

 

Well any instrument gauge can become quirky its just that most owners have just factory gauges to look at. My '94 Z28 voltmeter reads pegged high/over 18vdc normally but it does come down if batt is discharged. So i just use my $20 batt tester that checks the batt standing voltage w/eng off and i can load test the batt with a flip of a switch. Then it shows me charging voltage once the eng is started. Like said standing batt voltage should be in the 12.6-12.8vdc range and near 13.2vdc w/eng running - u may have to bump the throttle to get the alt charge going. Thats all there is to it and we shouldn't try to make it more difficult than that.

Those batt testers are so cheap and small i have at least 2 and usually carry one in the car as i didnt trust the high voltage reading i was getting. U can also make some long extension leads for a hand held voltmeter (i'm sure u have one and know how to use it) to connect to the batt terminals and watch batt voltage while driving.

Now if u do have low voltage at cruise u will need to troubleshoot that. Could have a short to ground, intermittent short, bad gnds, bad ECM gnd or bad dash gauge or even bad alt. It seems like u have intermittent voltage changes when u load up the batt/alt which really isnt that abnormal.

Hope this can help more than confuse.

 

Thanks for the help, everyone. Haven't done any diagnosing because I can't find my keys

 

Reach under the front of your seat and flip the u shaped wire down and back and lift your seat bottom out they are on the right side.

 

I don't know about the LT1 but it isn't a difficult thing to take out in the L98. I would take it out and have a rebuild shop test it in front of you and rebuild it if necessary.

 

Yea it's not hard at all.

 

Then take it out for them to see. PLEASE DO NOT GO TO AUTOZONE, ADVANCE AUTO, O'RILEYS, etc. Take it to a reputable shop that rebuilds the thing. I have brought alternators and starters they said were good to the rebuild shop. Pull it apart and you can see things are wrong but the test said it was OK.