Battery Issue?

With the engine running, use a mutimeter set on 30v DC and jump the battery terminals.

Turn on your lights.

You should have a reading of at least 13.85 volts at idle. If it is less then your alternator is crapping out.

There are 2 schools of thought on this;

1 measure the battery before you start the car... start the car if the voltage is 1 volt higher than the at rest voltage of the alt. It is working.... if not at least one volt at regular idle then the alt could be bad.

2 Start the car... at idle the voltage should be 13.5 / to 14.7 with a little reving of the motor.

IMHO 15 volts is high and could burn up the cells in your battery before I would change the alternator ...I would give a good look at the voltage regulator and check your grounding and current paths.

+2 with Joe, check your regulator first. 15 volts is getting high.

Thanks. I was wondering about the regulator as well. Had to replace it about 3 years ago for some reason I can't recall. Not sure if there is a way to test it or just replace it instead as a first measure. At rest without car running the volts are about 12.25 or so. Here is another video below, this time with lights on. At the beginning of the vido the car is at idle with lights on and volts read about 11.4 or so, then I take it up to about 2,000 rpm and volts pick up well into 14 on the meter. Also see my amp meter on the dash about 1/2 way into the video how it shakes around quite a bit when going from 900 rpm idle up to about 1,500 (and then after that at higher revs it settles out not shaking like crazy).

Just hooked up the volt meter to my Maserati, and ran it the same way just so I can get an idea what this should realy look like on the meter with a normal car. It was 12.4 prior to starting, then went to 13.50 while ideling, then to about 14 with some rev. Got about the same scenario with lights on. So in other words, things seemed to stay in a rather close reasonable range, not like with the Pantera going from about 11.4 idle up to 15 on higher rev.

http://www.youtube.com/watch?v=g8R0kxkM0nU

It's an alternator issue. 14.5 is ideal at idle. No lower than 13.8 with a full voltage load. Replace the alternator and the regulator. Your problem will go away.

Your battery may be on the way out as well. On a fully charged battery,12.5, at idle the car should read somewhere between 14.5 volts and 15 volts across the terminals.

14.5 would be perfect. 13.8 indicates the battery is not fully charged. It may also mean that it will not hold a full charge.

If it is more than two years old, replace it

Put in a 100 amp alternator.

Different mechanics will see it differently depending on what they have experienced.

Im a fan of the single wire internal regulator alternators. I removed the ford voltage regulator on my car completely and installed a 100 amp single wire. No problems with low voltage at idle. My fastback has the same low voltage problem at idle. It still has the ford voltage regulator. I will be removing the regulator and installing a 100 amp single wire shortly.

Went and did the simplest and cheapest thing first, and just changed out the regulator (free exchange at autozone since the other one had warranty). They looked at the back of it and saw brown marks around the black square portion of the regulator, and also that black square portion was indented where they said it should be flat. Their conclusion was that it had issues, so I got a new one (in the photo is that black square of the new one). So I thought, ah maybe that's it, and put it on and still had the same dim lights, and funky meter readings as before...crap! Next looking at the battery it is a 980 crank optima, but looking at my receipts I see I got it in 2006, so that may be next in line to change. I am now watching that to see how long it takes to discharge by just sitting for a while. Tried testing the car as well just with the headlights on and car not running for a few minutes figuring maybe the battery would peter out after a few minutes, and I even kicked on the fan a little bit to draw some more out of it. But voltage drop wasn't real bad just for that little test. Went from about 12.5 to 12.2 with lights off in both instances reading the meter. As you can see I am trying to avoid the alternator (wishing it isn't that in my dreams), because it means removing the bulk head, and I think I had to do drivers seat as well last time I was in that area, so I was trying the simpler things first. Or I could just leave it as is, as maybe it has always been this way. ItalFord seems to indicate it may just be the type of alternator & regulator type, and I have heard this too on the web. As long as it isn't overcharging, then no big deal to me.

ok, I'll chime in... This is an exercise of trying to fix something that isn't broken.

The voltage output of the alternator cannot keep up with the demand required when the headlights are on. Most low power alternators do not provide the rated amperage until higher in the RPM range. In other words, the output is small at idle.

Higher output alternators will correct the perceived issue, not because there is something wrong now, but because they provide a higher output at idle.

Unless it really bugs you, there is nothing to do as nothing is broken.

Have you ever see the same symptom on a motorcycle???

Scott

The wide range of charging system voltage Jan measured sounds as though the voltage regulator was not regulating, and voltage was increasing or decreasing based on alternator speed (rpm). That's a common failure mode for a voltage regulator. I would have purchased a new regulator too. Modern electronic voltage regulators normally regulate at about 14 volts, the voltage should never go higher than that.

If the car starts normally (easily) next weekend then the battery is probably OK. If the car cranks sluggishly or needs a jump then the battery needs to join me in retirement. As a last resort a good auto parts store should be able to perform a load test on the battery for you.

The Hall Super Pantera, of which this is one, had a high capacity/output alternator put in them. Either 100 amps or 130. In fact, Gary was one of the first to use a one wire alternator.

It wouldn't be a bad time to switch to a one wire system since it would eliminate the regulator from the equation entirely. Simplifying the Pantera is a good thing.

FYI I have killed three Optima reds in the last 5 years. The problem with that is I have to listen to the lecture from the distributor and they need to attempt to recharge the battery "properly" with their "special" charger. Well folks. I've got one too.

Three of them were DOA. Bene Morto.

I still use them because they are dry cells. That's the only reason. Well that and they don't freeze up when we get these freakin' Artic Vortex scenarios.

If your voltage is dropping lower than 13.5 to 13.8 across the battery terminals with the car idling and your accessories on, the issue is the alternator. Whether that means what you have is dying, the belt slipping (usually it will squeal when you load the alternator) or the battery is on it's last legs.

There in lies the cultpret(s). Optimas are weird batteries. They can go more than 5 years or not make it to two. Unfortunately even with them, they have gone "offshore" and quality control went out the window with them. Buyer beware.

Thanks for all the tips.

Scott: You may be right in that everything could be normal for the system that it is, and my alternator could just be the lower voltage type. Here is a photo I took about a year ago, but not sure if just a visual would determine amps or if there is a number on it or something: http://www.flickr.com/photos/1...426@N07/12080096356/

George: I did get a new regulator from autozone, put it on and all symptoms were the same with that one hooked up. Car has real strong crank when I start it, but I will probably have it load tested anyway to be sure. I can let it sit for at least 2 weeks with battery shut off switch, and it still starts right up strong. But I am with you on the retirement thing...one more year for me, and then I can stay home & tinker. Maybe then I would enjoy it more with time to tinker rather than seeing it as a chore trying to fix stuff.

Doug: My Group 4 car isn't one of the Hall Super Pantera's built by Hall, as it was a custom build with Kuntz & Craft build on the engine. I just checked my files on the build, but it didn't say anything about the alternator type or amps.

One thing I still find odd however, is how my Amp meter on the dash jumps around rather violent when going from idle to about 1,500 RPM, and then seems to calm down at 1,500+ RPM. That just doesn't seem normal to me, but who knows. You can see it in youtube below, about 1/2 way through the video.

http://www.youtube.com/watch?v=g8R0kxkM0nU

I have the same problem in a 80 vw that I buss to work. Napa's best battery, 5 replacements in one year and the warrantied alternator 6 time's?
Replacement parts are all junk. they work fine for a while then go south.
Once I am out of the warranty on these items these are what I am going to:

Alternator: Riverside Alternator and Starter, 951-354-2373, 9960 Indiana Ave, Unit #3 Riverside Ca 92503. All good reports from folks that use them. They also kick up the amps.

Battery: http://www.odysseybattery.com/ .
I have a 2003 VW Golf Diesel Battery in the pantera now that fits perfectly in the stock location that is still kicking. This will be hard to change as it has done so well but I think the odyssey will be a good choice.

I have way to many cars, all maintained well and I hate inferior parts and many of the parts houses are pushing junk, If I can get my parts from the factory/dealer I take the hit on pricing and most of the times I have no worries.
On the rare occasion I end up at O'reilly's , Napa, Auto zone etc most of the time it's nothing but grief.

The voltage on my alternator just prior to it giving up jumps too. its the diodes in the alternator not quite working correctly and regulating. It sound like the set up worked for a good while, I would have your alternator rebuilt in that case. good luck. Mark

The Beast; 0-55mph in 45 sec. can reach Mach 70mph with tailwind. 50mpg all day.
1.5 normally aspirated diesel 300,000+ miles. won't die!

If I were you I'd cut my losses and go to this.

http://pantera-electronics.com/gm12sialternator.htm

I've seen Cobras do that with the Smiths gauges but the Pantera not that crazy of a fluctuation? Look out for that gauge too if it's an original.

They have been known to short out and the battery grounds to the chassis through it.

It will melt more than the gauge if it happens and there is no way to stop it.

I think your issue is just a too small of an output on the alternator. You need to go to either a 100 or a 130 amp alternator.

Lots of folks have had great success going to the GM one wire set up.

I personally have a 130 amp alternator. Shows no issues at idle or anywhere else. It can be a little noisy at times though.

The one wire will eliminate the need for the remote regulator. It will have an internal one.

Eliminates some of the guesswork usually but I have used them and you can short them internally so I'm not sure if it's an upgrade with the internal regulator or not?

The internal regulator is really intended to be used with a car with a "whole car fuse". Having said that, by the time the fuse blows, the alternator is usually blown also.

The problem with the external regulator is that it has internal points in it similar in thought to what a distributor has.

The points can burn and/or carbonize and also can oxidize from the moisture in the air.

Took the battery to autozone, and it checked out good. So I suspect the alternator or maybe connections like you guys said (all of which I can't easily get to without taking out the bulkhead). That amp meter shakes like crazy pretty violently and the dash lights flicker too, and i never really noticed that before. Now this makes sense why my windows move real slow over the past year or so. I thought the motors were going out, but today I operated them and reved the engine at the same time and they moved up and down like a champ.

Anyway not sure if the alternator change is something I can do on my own (or have the patience for) so I will probably take it in, then if it isn't the alt, then they could Dx better than me.

Thanks for all the tips. At least I ruled out the regulator (replaced) and battery.

I drove to the autozone once and had them check my battery. They pronounced it good. Then I tried to start the car in their parking lot and the battery wouldn't turn over the car. They replaced the battery then. I use O'Reillys now to check batteries! :<)

quote:

Originally posted by GTPowered:
I drove to the autozone once and had them check my battery. They pronounced it good. Then I tried to start the car in their parking lot and the battery wouldn't turn over the car. They replaced the battery then. I use O'Reillys now to check batteries! :<)

I'm sorry, it was O'Reillys that did the battery check. I just thought they were the same company for some reason. They did a battery check that took about an hour and said all was ok. I have no warranty on it, so from their perspective it would be better to test it bad so I would buy another. Maybe I will be adventurous and remove the bulkhead and see if an alternator change is something I could do myself. I presume all the work to replace it is done through the bulkhead area.

Took the car to Tommy Hodges of Extreme Pantera, and he put in a 100 Amp alternator with single wire regulator. BadaBoomBadaBing, works fine now, with idle volts about 13.6 or so and revving gives about 14.6 or so. Amp meter on the dash is nice and steady now too. Damn those lights are bright on idle now. I guess now I have no excuse for driving to Cars & Coffee at 5:30 AM in the dark. Thanks for the tips ruling out other things. My bulkhead over the engine is separately built from the entire back panel, which I made the job a little easier in and out of the engine area. I recall my original orange Pantera had one large panel, so I had to take the whole deal out including one side seats, which was a pain.

Great Result - well done - now drive the hell out of it