Hi guys,

Went to first car show of the season today, anc the car was nothing but trouble.  Luckily the show was at my friends firestone shop, so they helped out....

On the way there, I was losing voltage (have a volt gage under dash).  Car would charge, then Id hear a pop & screech, then it would start to lose voltage.  Car kept running, but eventually got to the point of no lights. gages, etc.  Occasionally would come back up, then id hear a quick screech, and same thing again.  So I figured alternator, right?  (car has a 1-wire alternator in it) Not so fast....

So we swapped out the alternator for a new one (2 actually), and it still doesnt show charging (yes, internal regulator, so that should be new too).  He load tested the battery and it came back bad (about 140 cca under load).

We put enough of a charge into the battery to get home (barely) and every once in a while on the way home, id have the same quick screech with the new alternator, and towards the end the engine would cut out when it did it.  got home (with a lot of prayers on the way!) and the battery showed about 9v.

For kicks, I tried disconnecting everything non essential (pwr top wire, stereo, etc) and had same results.  Checked and have same batt voltage at bacl of alternator with power off.

My friends theory is that the battery has an intermittent shorted cell, and thats what the problem is.  I could buy that, but I cant get my head around why the alternator wouldnt show charging?  Does his explaination make sense?

Alternator is wired with output cable to the + on starter solenoid (and has been for years w/o problem).  All good grounds, all wires are tight and in good shape.  At this point, I cant think of anything else it could even possibly be, but ???  Am I missing something, or would a bad cell cause this?  Like I said, we tried 2 alternators with the same result....  Any thoughts or anything else to check before I buy a new battery?

THANKS!

Also when running, if you were standing next to the car, you could occasionally hear what I would describe as a faint electrical crackle prior to the screech sound...and it sounded like it was from the battery area.

Ron Grove

Wauconda, IL

Ron-Why not swap a known good battery just to test your theory.Doesn't have to fit the battery tray-you are only trying it at idle and see if the alt. charges.I dont know why a bad battery  would affect the alternator but try a good battery and see.

  

Yes, I may do that tomorrow. Its a pita to get the battery out of my dd to test, but I miight try that. Either way the battery tested bad under load so I probably need one, but id hate to do it and find yet another problem!

Thanks!

Ron Grove

Wauconda, IL

Ron:

The battery tested bad.  Replace it.  If there is still a problem, it is there whether the battery is old or new.

John - "The Hoosier Hurricane"

Ok, so I just tried the battery out of my daily driver.  Its about   a year old.  Same result.  Shows about 12.4v running, 12.5 when shut off.  Im really stumped since this thing is wired so simply....any ideas?

Ron Grove

Wauconda, IL

Maybe Steve Metzger will see this post.Pretty sharp guy on electrical stuff.Maybe you should put this problem in the technical posts?

  

So I also just tried hooking a jumper cable from neg terminal to alternator body just in case it was a ground issue....no change.

Ron Grove

Wauconda, IL

Ron: You say the same result (voltage) with your daily driver battery. But are you getting the noise etc? If that battery is fully charged, your replacement alternator may not be kicking in. Off the top of my head the squeeling sounds like a slipping belt. No?

Paul

I had a noisy alternator once years ago.Turns out a bad diode will cause a high pitched squealing noise.Is it possible the wire feeding your voltmeter is grounding or has a short in the wire?

  

Hi Guys,

A little clarification:

I didnt hear any weird noises with the "new" battery.  however, I also didnt run it too long with it in there, since it wasnt mounted well, etc.

Volt meter at the battery terminals read 12.4v while running; 12.5 while not running. 

Reading on the volt gage under dash has been/is consistent with voltmeter at terminals

Belt has been tightened/retightened

Revving engine to >2k (in an attempt to get alternator to kick on) yielded no change

Gage array under dash is fused; would have thought that would have blown if there was a short?

Previous to all of these problems, the gage under dash would regularly start at ~12v, then when the engine is revved to above about 1200, the needle would kick up to the normal 14.5, and would stay there until car is shut off.  Because of that, im skeptical that it doesnt kick on because the battery is fully charged?

All wiring in the car was new 8 years/about 17k miles ago

Is it possible that the bad battery killed the new alternator on the 25 minute drive home?

Ron Grove

Wauconda, IL