Welp...Think I lost the Alternator

[Joe K. 99 Zeee!!]

Went to snag some Diet Coke today...$10/4-12 packs at Safeway w/ $10 mail in rebate...

On the way back, I notice the turn signal blinking slowly. A/C isn't putting out. Check Guages comes on and sure enough, voltage is deep in the red. Then the ABS and Traction Control go out. Seems like it's shutting down unecessary systems to preserve battery power.

No place to work on her here, so she's going to the shop tomorrow. Just turned over 79k. My last car didn't lose an accessory till 118k (starter) and then 127k (ac compressor). Seems to be a little early for an alternator.

Could it have been this horrendous rain in D.C.?? I noticed a slight squeeking from the accessory drive area that started just a few days ago.

[fastTa]

Just replace the alternator yourself. That is probably the easiest thing to do on an LT1.

If you have enough room to lean over the motor in the driveway, you have enough room to R&R the alternator.

As for the life expectancy of an alternator.....there isn't one. They can go out at any given time. One of the primary causes of a bad alternator is a battery that has lost it's ability to properly maintain a charge. Most people don't realize that.

It would be a good idea to have your battery load tested as well before you run the new alternator.

[Z Ya Later]

Just replace the alternator yourself. That is probably the easiest thing to do on an LT1.

If you have enough room to lean over the motor in the driveway, you have enough room to R&R the alternator.

As for the life expectancy of an alternator.....there isn't one. They can go out at any given time. One of the primary causes of a bad alternator is a battery that has lost it's ability to properly maintain a charge. Most people don't realize that.

It would be a good idea to have your battery load tested as well before you run the new alternator.

Ok, look at his sig. or his user name...its not an LT1 lol

But still, alternators are a breeze to do. I'd do it myself.

[fastTa]

Ok, look at his sig. or his user name...its not an LT1 lol

But still, alternators are a breeze to do. I'd do it myself.

Just replace the alternator yourself. That is the easiest thing to do on an LS1.

Better.

[Joe K. 99 Zeee!!]

Update:

I had the shop down the street do a start and charging test. They pronounced the battery DOA. So I got a battery, threw it in, and according to them it passes the test.

I'm still not sure. On the drive back I watched the voltmeter closely. With A/C and stereo on, it's reading just above the line between 8 & 13 volts. That's right around 11 volts. With engine off and key in run position it reads maybe 12 volts. For a moment while driving stayed at 14 volts, but only for maybe 10 seconds.

Owner's manual says to worry only if it goes below 11 and stays there. It's borderline and making me uneasy.

[fastTa]

Update:

I had the shop down the street do a start and charging test. They pronounced the battery DOA. So I got a battery, threw it in, and according to them it passes the test.

I'm still not sure. On the drive back I watched the voltmeter closely. With A/C and stereo on, it's reading just above the line between 8 & 13 volts. That's right around 11 volts. With engine off and key in run position it reads maybe 12 volts. For a moment while driving stayed at 14 volts, but only for maybe 10 seconds.

Owner's manual says to worry only if it goes below 11 and stays there. It's borderline and making me uneasy.

If in fact your alternator is going south, the bad battery was what caused it. Alternators are not designed to maintain the entire system by themselves. It is merely a means of keeping the battery charged to full capacity.

It is normally cheaper and better to just have the existing alternator rebuilt rather than buy a new one. And most alternator shops will give you a 1-2 year warranty.

[Kevin - Blown 95 TA]

Kev, if the alternator couldn't run the whole system by itself, the battery would eventually drain and go dead. The battery just starts the car and acts like a big capacitor the rest of the time to smooth out the ripple current so the electronics don't freak. In the generator days, the battery ran the car electrics in low rpms until the engine ran fast enough so that the generator made more voltage than the battery and started charging it. Alternators do a pretty good job at low rpm unless you got 1000 pounds of stereo amps or something. They have to work especially well in EFI cars.

[fastTa]

Think of the battery as a big water tank and the alternator as a backup water resevoir. The entire electrical system is plumbed directly to that main water tank(battery). The electrical system is pulling that water directly from the main water tank and the alternator is simply keeping that main water tank full enough so as not to starve the system.

The main difference between the older generators and today's alternators is that the generators directly generated DC current. Alternators orginally produce AC, thus the name alternator. Then that AC must be rectified into usuable DC since during the first 180 degrees, of rotation, the current direction is positive, and during the second 180 degrees the current direction is negative.

Also because of this, alternators have no need for a commutator which makes the alternator much more rugged and light, and allows the alternator to be overdriven by up to 4 times the engine speed in some cars.

On alternators, a voltage regulator is needed to dictate how much energy is required to be allowed from the rectifier bridge. This is why the voltage regulator sensor is connected to the positive side of the battery. The alternator only releases energy when it senses the battery voltage is too low.

This is also why bad batteries will in almost all cases cause an alternator to fail as well. The alternator is not designed to maintain current for any extended period of time.

The battery is by far the main source of energy for our electrical systems. The alternator just keeps it charged.

The battery has very little to do with "smoothing" rippling. That is the primary responsibility of the three-phase windings found in most alternators today.

[Joe K. 99 Zeee!!]

I took some readings this morning myself. Battery shows 12VDC with the key in the run position, engine off. Engine on, it shows between 11.5 to 12.5. It jumped to 14.5 once for a moment. At times it was very briefly showing 6-9 volts with the A/C and lights on.

Service manual says 13-16 volts after running for 5-7 minutes. It's certainly not up to spec. I'll have to wait till later to fix it. I'm going to enjoy some time with the family today!

Thanks for the help! Most likely alternator due to my last battery. From now on, I'm not to change them out. After 4 years, I might as well just get a new one. After that long, the prorated warranty is not going to do much good.

[Izzy]

I'd change the alternator myself .. very easy to do .. took me 20 minutes ... i'd head over to a place like autozone with your old alternator and battery where they do free testing on the stuff. also .. since your DIY .. throw in the extra 20-30 bux and get the alternator with the lifetime warranty ... the other ones only are a year... saves you headache later if a bad battery causes an alternator malfunction....

[fastTa]

I took some readings this morning myself. Battery shows 12VDC with the key in the run position, engine off. Engine on, it shows between 11.5 to 12.5. It jumped to 14.5 once for a moment. At times it was very briefly showing 6-9 volts with the A/C and lights on.

Service manual says 13-16 volts after running for 5-7 minutes. It's certainly not up to spec. I'll have to wait till later to fix it. I'm going to enjoy some time with the family today!

Thanks for the help! Most likely alternator due to my last battery. From now on, I'm not to change them out. After 4 years, I might as well just get a new one. After that long, the prorated warranty is not going to do much good.

Whenever you see a fluxuation like that in voltage from the alternator, it usually indicates a burnt stator, bad voltage regulator, or rectfier bridge. Either way, it sounds as if it needs to be replaced.

[Kevin - Blown 95 TA]

Think of the battery as a big water tank and the alternator as a backup water resevoir. The entire electrical system is plumbed directly to that main water tank(battery). The electrical system is pulling that water directly from the main water tank and the alternator is simply keeping that main water tank full enough so as not to starve the system.

The main difference between the older generators and today's alternators is that the generators directly generated DC current. Alternators orginally produce AC, thus the name alternator. Then that AC must be rectified into usuable DC since during the first 180 degrees, of rotation, the current direction is positive, and during the second 180 degrees the current direction is negative.

Also because of this, alternators have no need for a commutator which makes the alternator much more rugged and light, and allows the alternator to be overdriven by up to 4 times the engine speed in some cars.

On alternators, a voltage regulator is needed to dictate how much energy is required to be allowed from the rectifier bridge. This is why the voltage regulator sensor is connected to the positive side of the battery. The alternator only releases energy when it senses the battery voltage is too low.

This is also why bad batteries will in almost all cases cause an alternator to fail as well. The alternator is not designed to maintain current for any extended period of time.

The battery is by far the main source of energy for our electrical systems. The alternator just keeps it charged.

The battery has very little to do with "smoothing" rippling. That is the primary responsibility of the three-phase windings found in most alternators today.

Nice lecture, but that's not how it works. The alternator puts out a regulated 13.8-14.2V or so which is a higher voltage potential than the 12.6V battery has. The alternator puts current into the battery, which is at a lower potential, at the same time as it supplies the rest of the car with current. Current is NOT moving from the battery to the electrical system as the alternator is charging it. If you don't believe me, put an ammeter on both sides and see which direction the current is going. If current is going into the battery, it cannot also be coming out at the same time. And the battery is always charging as you drive the car (if everything is working). Furthermore, the battery DOES smooth out the ripple, even on a 3 phase system, because the battery has internal capacitance as well as internal resistance. Now, you can try to violate Kirchoff's Voltage Law, but YOU WILL NOT WIN. Comprende?

[raroZ28]

now ya did it kevin. I give this thread two more days before it's locked, it's what he does best man you should know this by now.

[fastTa]

Nice lecture, but that's not how it works. The alternator puts out a regulated 13.8-14.2V or so which is a higher voltage potential than the 12.6V battery has. The alternator puts current into the battery, which is at a lower potential, at the same time as it supplies the rest of the car with current. Current is NOT moving from the battery to the electrical system as the alternator is charging it. If you don't believe me, put an ammeter on both sides and see which direction the current is going. If current is going into the battery, it cannot also be coming out at the same time. And the battery is always charging as you drive the car (if everything is working). Furthermore, the battery DOES smooth out the ripple, even on a 3 phase system, because the battery has internal capacitance as well as internal resistance. Now, you can try to violate Kirchoff's Voltage Law, but YOU WILL NOT WIN. Comprende?

You're right.............

[Joe K. 99 Zeee!!]

It's ok...my problem is fixed now. Alternator's been replaced. I'm seeing a steady 13-16V, even with A/C, lights, and stereo on.

Thanks!!