Okay, I replaced my battery and the car starts and runs like a dream....but I don't like the way the battery (voltometer?) is looking(I noticed a slight drop in the needle driving home) so I pop the hood and look at the alternator and don't see any movement inside the case..and trhe casing wasd hot as hell....does this mean the alternator is bad? Also..are discount part store alternators POS's?

 

When you say the alt was not moving do you mean it was not spinning with the belt? If so then get rid of it. Expect to pay about $90 - $100 for a new one at an auto parts store. Suggest you go with NAPA and avoid those other places

------------------
92 Camaro RS, LO3, 5-spd, T-tops

Performance:
K&N Open Air Filter, Edelbrock performer TBI intake, Fastchip Prom, Timing +4 degrees, Centerforce clutch, Xact 8mm wires, SLP 1 3/4" Headers (coated), Flowmaster Catback Exhaust, Z28 Grille w/aftmkt fog lamps, MacEwen white-face guages
Electronics:
Alpine 8030 Alarm System, Valentine One Radar Detector (How did I ever drive without one?), Pioneer DEH 7450 Head Unit w/6-pack CD changer, Pioneer DEQ 7600 Sound Processor, 2 Kenwood KAC-846 Amps powering 2 12" Pro Red subs, 2 Pioneer 6x9 and 2 MTX 4x6 speakers.
NEXT UP: TBI mods, 3.42 gears w/Torsen posi

 

Wait just a second, now....The pulley with the little fan was spinning, but I don't think the motor inside( with the wire all wound up) was spinning. Is that what you meant?

 

That's the stator, and it would probably be pretty difficult to tell if it was moving or not. Test your alternator...if you don't know how, most places will do it for free. It should be putting out around 14V. If it isn't, a rebuild kit is cheap and very easy to do. Everything is pretty self-explanatory.

 

Well maybe I just bein a little paranoid. I really only looked at it on the drive home from the parts store. Where could I get it checked for free? I don't really want to drive around much not knowing.

 

Just call your local auo parts store (Auto zone, etc) and ask them if they can test your alternator. Once you find a place that does, off you go!

 

An easy check (albeit crude) to see if the alternator is working is to do the following at night.

With the lights "on" and the engine at idle, rev up the engine (2000-2500 RPM) and the lights (dome and/or headlights) should get brighter. When going back to idle, they should get dimmer. Try the same with more accessories (fan on "high") "on" for a more dramatic difference in the brightness, as well as a faster fan speed, although at least for me, it's difficult to notice the difference in fan speed - I can easily see the difference in light intensity.

If the alternator is working, or, uh, at least putting out some current, it will make the lights get brighter the faster it rotates (faster engine speed). When the engine slows down (idle), the alternator is moving slower and thus, not putting out as much current. Less current = less voltage = dimmer headlights.

If you do not see any change in the brightness of the lights, then

1. the alternator is not putting out enough current even at high RPM's (a degraged alternator - have it tested) - the lights would not be as bright as they should at both idle and at speed - this is not a common problem,

2. the alternator is putting out enough current at idle (you'd have a very good alternator if this were the case!) to keep up with the demand of the load, which is why you should try this test with all the accessories "on" to present a higher load to the alternator when its output is the lowest (at idle) - the lights would be their brightest at both idle and at speed so you would not see any change,

3. you cannot deferentiate differences in light intensity well,

4. or the alternator is bad (it is not putting out any current/voltage) which, more than likely, will be the problem. Have it tested (you can do it free (!) at many auto parts stores) to be sure.

[This message has been edited by Stuart Moss (edited June 07, 2001).]

 

Stuart,

I have the same basic problem. I used my multimeter to test the voltage at the batt. w/car off. I got 12.8v. With the car on, I got 13.8v. Then I changed the badly needed belt, cleaned all connections at the alt. and batt. Then it pulled 14.2v. Well I was happy with the $18 fix.

Well the other night I was sittin' at a light and rain came. It was hot so I rolled up windows, turned on windshield def. (A/C), rear def., and wipers. My voltage gauge damn near hit the left peg. So I went home and tested it with all the same stuff on. I only got 12.8v with all that stuff on. I tested just the batt. again and got 12.8v from it w/o car on. So I took off the alt. and headed to AutoZone. They bench tested it @ 14.2v. So I'm thinkin' "WTF?" My buddy and I went back to my house and he noticed the green Delco batt. dot was not there. (Dumb_ss me didn't notice.) Low water in batt. Back to A.Z., buy batt., put it in and 14.2v w/ car on. 14.0v w. all the same stuff on mentioned earlier. I thought I fixed it. Today, same situation. Rain again, and gauge hit left peg again. Tested it again with same voltage results as before the new batt.

Could it be the regulator in the alt? Do they go out intermittently? Could it have acted OK at A.Z., then screwed up under heavy load, or under heat, kinda like a starter solenoid? I just don't wanna spend $85 on new alt. for it not to work.

Thanx,
AJ

[This message has been edited by AJ_92RS (edited June 07, 2001).]

 

AJ,

You have an interesting problem. Such a sudden and dramatic drop in voltage, in my opinion, would not lead me to suspect a bad battery or alternator. I'd guess a bad connection (dirty and/or loose) that is intermittant. It could also be something that caused a very large load to the electrical system. Perhaps an intermittant short to ground with a large wire (if it was a small wire, you'd have seen smoke).

12.8 volts with the alternator working normally means that the alternator is not charging (or the battery is extremely low). 14.0 volts under load (as you previously measured) is certainly a good and normal level. Less than 7-8 volts ("needle pegged to the left") indicates a dead battery or the voltmeter stopped working [wire came off, etc.]). A good battery will take at least an hour, probably hours, to get that low even with all the accessories "on".

Try the same test (alternator running with all the accessories "on" both at idle and at speed [~2000RPM]) with a fully charged battery. What are the two voltages???

Try to charge a low or very low battery with an external battery charger. CS-130 alternators have a known cooling problem that can damage the rectifier/regulator when tasked to profide a lot of current (>60 amperes) for an extended time (>20 minutes) without time to cool. Summit and Whitney both sell an alternator rebuilding kit which will help cooling ($50).

I'd suspect the short to ground or poor connection(s) cuase even more if:

1. The condition of the new battery is good (many stores will test them free).

2. The alternator tested good (again).

Let us know what you find.

//Stuart

[This message has been edited by Stuart Moss (edited June 08, 2001).]

 

Well I think I exaggerated a bit 'cause I was pissed, and still am. It doesn't really go to the left peg, it just seems like it because of the way that our gauges are set up. Like I said, it was reading 12.8v when tested with the voltmeter.

Is 12.8v OK for a battery? I will charge the batt and see how it goes. Does the rebuild kit you mention have a different designed fin/pulley, or do I just use the old one? Just curious how the kit helps cooling. And am I gonna be able to get the damn thing off without an air gun? I've rebuilt alts before, but it was in shop class where we had air tools. They make life so much easier. Oh, and I should have mentioned the car, or put in my sig. Sorry

Edit: Just realized what your gonna think when you see 170K miles. It needs to be rebuilt, huh? And thank you.
------------------
92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford 2ch. to 2 MTX 12" subs

[This message has been edited by AJ_92RS (edited June 08, 2001).]

[This message has been edited by AJ_92RS (edited June 08, 2001).]

 

AJ,

Some interesting (at least to me) tidbits about lead acid batteries -

12.8 volts is not only okay, it's ideal for the open terminal voltage of a 12V battery.

There will be what is known as a "surface charge" that will give you a higher reading immedately after being charged. For example, it's common to see ~13.4 volts immediately after turning the car off, but then it will drop down to 12.6-12.8 volts. It is important to remove this surface charge if you're going to test it. You can remove this surface charrge by:

1. Let the battery sit for 2-3 hours,
2. Give it a slight load (such as turning on the lights for ~5 minutes), or
3. With an battery load tester, apply the load at half of the CCA rating of the battery for 15 seconds.

For sealed batteries, you cannot determine the state-of-charge by measuring the specific gravity of the electrolyte, so the next best way is with a digital voltmeter (preferably one that has better than 0.5% accuracy). Some batteries have a built in hydrometer which only measures the state-of-charge in one of the cells. If the indicator is clear or light yellow, then the electrolyte level is low and should be refilled. If the battery is sealed, discard it.

Here is a table of voltages that equate to the state-of-charge.

1st COLUMN: Open Circuit Battery Voltage
2nd COLUMN: Approximate state-of-charge
3rd COLUMN: Average Cell Specific Gravity

12.65+ ---- 100% ---- 1.265+
12.45 ------- 75% ---- 1.225
12.24 ------- 50% ---- 1.190
12.06 ------- 25% ---- 1.120

If the temperature of the electrolyte is below 70°F (21.1°C), add 0.012 volts (12mV) per degree below 70°F to the voltage readings.

If the state-of-charge is below 75% using either the specific gravity or voltage test or the built-in hydrometer indicates "bad" (normally dark), then the battery will have to be recharged before proceeding. Replace the battery if one or more of the following conditions occur:

1. If you have more than 0.050 difference in the specific gravity reading between the highest and lowest cell (due to a weak or dead cell[s]),

2. If the battery will not recharge to 75% or more state-of-charge level or if the built-in hydrometer will still not indicate "good" (usually green which equates to 65% state-of-charge or better),

3. If the battery measures zero (0) volts (indicating an open cell),

4. Or if the digital voltmeter indicates 10.45 to 10.65 volts. This will indicate a shorted cell. This could be caused by some plates touching, sediment build-up or "treeing" between the plates.

TO LOAD TEST A BATTERY:

If the batteries state-of-charge is 75% or higher or has a "good" built-in hydrometer indication, then load test the battery by one of the following methods.

1. Turn the headlights "on" for five minutes,

2. Disable the ignition (remove the power cable(s) to the coil) and crank the engine for 15 seconds with the starter motor,

3. With a battery load tester, apply a load equal to 1/2 of the CCA rating of the battery for 15 seconds, or

4. With a battery load tester, apply a load equal to 1/2 the OEM cranking amperage specification for 15 seconds.

During the load test, the voltage on a good battery will NOT drop below 9.7 volts with the electrolyte at 80°F (26.7°C). (If the electrolyte is above 80°F, add 0.1 volt for every 10° above 80°F until you reach 100°F. If below 80°F, subtract 0.1 volt for every 10°F until 40°F). After the load is removed, wait five minutes and the battery should "bounce back" to the 50% state-of-charge level or above. If the battery drops below the minimum test voltage, does not bounce back, or will not start the engine, then you should replace it. If the battery passes this test, you should recharge it to restore it to peak performance (remember, alternators were not designed to recharge dead batteries for reasons detailed in previous posts).

See my comments at: https://www.thirdgen.org/messgboard/...ML/001629.html for some common reasons why battery's go bad. Note the paragraph above "EDIT #2" about buying new batteries that could be a candidate for a battery with a short life.

-------------------------------------------

Regarding your question on the rebuild kit. Both kits (available from Summit and Whitney) are identical. "Iceburg Alternator Conversion" was on the instruction sheet, but I'd don't remember the manufacturer's name. The kit includes the front bearing (same size), a larger rear bearing (larger to aid in cooling), brushes, rectifier and a rear aluminum housing (no regulator is included). The reason for the new rear housing is to accommodate the larger rear bearing as well as increasing the surface area of the aluminum by incorporating a small section of finned area - all to aid in cooling. This manufacturer has two kits, one is the standard kit ($50) which is the one I got, and the other is a higher output kit ($100) that boosts the output to 140 or 150 amperes. Of note is that even with their modifications, they still recommended not to use the alternator for extended periods (>15 minutes) at a high output (>50 amperes ???) as it will still get hot and potentially damage the rectifier. They recommended NOT to recharge a battery with the alternator (because of the overheating problem). If you have to, let it cool down every 15 minutes or so. So far, I'm happy with it.

I know what you mean about removing the front nut without an impact wrench, which can easily be done! I just purchased a 15/16" (I think that's the size) 3/4" socket and used an allen driver inserted through the 3/4" hole (my allen driver would not fit inside a 3/8" socket...). I used pliers to hold the 15/56" socket stationary while turning the allen wrench to remove the front nut. I used blue Locktite upon re-assembly. If you have problems holding the socket, you could file/grind the sides to create "flats" for a better grip.

You'll have to "pop" the front bearing out because there's a thin aluminum seal around the bearing lip holding it in place from the factory. This is easy to do (I used a 4" vice). A bearing retainer is included in the kit for the new bearing. If you see a bearing retainer holding the front bearing in place, you'll know it's been rebuilt before.

I removed the rear bearing from the rotor with a battery terminal remover ($10). I didn't have a gear/bearing puller. Sometimes the rear bearing will come off when you separate the case half's though.

You'll have to crimp (I crimped and soldered) the new rectifier in place of the old one because you'll be using the new rear housing.

I've heard of some aftermarket alternators (CS-130 style) that have an additional internal fan to aid cooling. Definately a good idea. However, the "Iceburg" kit did not.

Let me know how things work out.

//Stuart

[This message has been edited by Stuart Moss (edited June 08, 2001).]