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I tested first thing this morning. 14.1 volts... Lol. It started settling down almost immediately but I'm thinking it is fine. How bad my old alternator really was I don't know. At this point I don't care. It was 12 years old and that's old enough for me. Dropping down to 13.3 seems a bit low. I'm going to replace the battery as well considering my battery is between 5-6 years old. After looking at Consumer Reports reviews I'm going to go with the Everstart Maxx 24f. It's made my Johnson Controls and they are known to make good batteries. 3 years free replacement 5 years pro rated.
That's an excellent warranty compared to most other batteries. I've traditionally gone with Costco's battery choice but can see the wisdom of maybe paying a bit more for a brand that is confident in their product's reliability. Have you ever considered Optima type battery? They're supposed to last even longer. They're popular in the boating world when a combination start/deep cycle is desired. Actually a marine supply/boating discount chain such as Boat US and Boater's World can be an affordable source.
Edit: I see that Walmart offers Everstart Maxx. Bound to be an inexpensive but quality choice. No need to spend double to triple for an Optima.
I tested first thing this morning. 14.1 volts... Lol. It started settling down almost immediately but I'm thinking it is fine. How bad my old alternator really was I don't know. At this point I don't care. It was 12 years old and that's old enough for me. Dropping down to 13.3 seems a bit low. I'm going to replace the battery as well considering my battery is between 5-6 years old. After looking at Consumer Reports reviews I'm going to go with the Everstart Maxx 24f. It's made my Johnson Controls and they are known to make good batteries. 3 years free replacement 5 years pro rated.
Lavrishevo.....Your replacement alternator is behaving exactly as my original alternator. I too start out at 14.1-14.2 at startup and immediately start dropping. I probably settle in the mid 13s. One thing I didn't realize you hadn't already done was to replace the battery. I always think it's a good idea to do the Alternator and Battery at the same time so that at least you are starting out with an even playing field. Are you still planning on replacing the alternator again? Sometimes we get too involved with the numbers rather than how our cars are behaving in general. Keep us posted and good luck.
PS. I replaced my battery 3 years ago with the same battery the car came with: AC/Delco. They prorated the battery and it cost about $100.
No, I'm going to leave everything as is. I don't trust the Autzone machine. It gave me the same error between my old and new.
I replaced my battery with the one mentioned above and I think my alternator is perfectly fine. My original was most likely fine. Never metered it in the morning but it would charge at 13.7 at times during the day. It's reassuring to have a new one and battery.
I think the lesson here is looking at voltage is not really the correct way of truly testing the alternator. From calling around and speaking to a few techs amperage is what you really need to measure. The car runs great so I'm just going to leave it be. It kind of sucks to spend money on something that did not necessarily need to be fixed but on the flip side I should not have mess with it for another 10 years.
I like Optima. I had a Yellowtop in my LS400. I don't know why they are not included in the Consumer Repotts ratings. Since I just spent all this money on a alternator I figured a good battery rated by Consumer Reports at 1/2 the cost is perfectly fine.
No, I'm going to leave everything as is. I don't trust the Autzone machine. It gave me the same error between my old and new.
I replaced my battery with the one mentioned above and I think my alternator is perfectly fine. My original was most likely fine. Never metered it in the morning but it would charge at 13.7 at times during the day. It's reassuring to have a new one and battery.
I think the lesson here is looking at voltage is not really the correct way of truly testing the alternator. From calling around and speaking to a few techs amperage is what you really need to measure. The car runs great so I'm just going to leave it be. It kind of sucks to spend money on something that did not necessarily need to be fixed but on the flip side I should not have mess with it for another 10 years.
From what I've been reading, the inexpensive multimeters cannot effectively measure our car's amperage without destroying the multimeter. Most only go up to 10 amps.
I have a nice volt / amp ac / dc meter that goes up to 400 amps but it is a really pain to do it on the 430 because of where the alternator is. I can't get to it with my cable length. You have to go from the lead on the alternator itself to the battery. Same deal voltage drop test.
I got my curiosity up again and checked my battery and alternator voltage just a little while ago. After sitting for a number of hours my battery read 12.76 with the car off. That shows that the battery if fully charged. I started the car up and the voltage jumped to 14.36 while slowly dropping. Now here is where I noticed something different. When I put a huge load on the car at idle (a/c, rear defroster, headlights, etc) the voltage dropped to 12.76. I got into the car and revved the engine to about 1500rpms for about 10 seconds and then ran out to look at the meter. It was then reading 13.76 This I later found out is because the alternator's amperage increases with engine speed. So know I can also see that engine rpms have a great effect on the alternator output as well as the outside temperature. Higher outside temperatures produce less alternator output than very cold temperatures. If you are idling your car with every single accessory on, the car is not charging as it should. But then again, who does that for any length of time? All I do know is this. With just about 98% city driving, my battery is usually close to fully charged and I have not had any issues at all. I've even tried watching my headlights at night against the garage door when I step on the brakes, or put on accessories and once again their intensity stays the same. I think this post is starting to become overkill for me! lol I need to find something to do!
The voltage is directly tied to amperage load from what I can gather. I did the same thing. Loaded up with heater on high, lights, radio, and I was holding at 13.66 at 2000 rpms. I also wonder if the computer comes into play on 04-06 with the 4 pin alternator.
I know this is an old thread but I think I'd better to write some about those 4 pin alternators. The added pin has a signal name "C" which is the control line. This pin exists to get the control signal from the ECU. Toyota has started to use a technique to control the alternator's charging level starting early this Century. See the chart below. Depending on a condition of the battery, the alternator changes the charging level Highand Low. Also the temperature compensation is done. The purpose is to improve the gas mileage and longer battery lifespan.
These cause the voltage at the +B line sometimes higher than 14V and sometimes roughly 1V lower than that. When the ECU monitors and judges that the battery is charged enough, it forces the alternator to work as Low mode sending the control signal to "C" pin. Incidentally, the chart is from an official Denso's document.
This is the reason why you get a bit higher than 14V right after the start-up and goes down to 13V order as you run and the temperature goes up.
The old charging checking equipments used at major parts shops are now mostly outdated.
07-17-15, 07:17 AM
