The death of a charging system

[Buzo]

Yesterday, Igot problems with my charging system that i am still trying to resolve. It was of the type of the charging light turning ON.
So the car fired up that morning, but I left it in the garage and asked my wife to bring me to work.

In the eveningI made my standard procedure for problems like this, fired the car up, checked fuses, teminals, etc, removed the battery terminal and the car died. Every time. So I replaced the alternator,tested the car, the voltage reading was full 13.5 V, but after 5 minutes the alt light came ON again and the voltage reading felt to 11.5V.

The light was blinking on/off very fast at idle and it only goes off when the revs are above 1500 rpm.

In summary I need to keep analyzing the problem, but something unique is that I captured with my logging system thestarting of the failure, I have logs when the car was OK, full charge at 13.5 V even at idle, to the time when the alt lightturned on.

I will post charts of the battery voltage during the last week just for fun (it won't help to solve problems). But we can see how the average was steady and then became lower and lower. I noticed it in my dash and I knew something was wrong, but didn't do anything about it until I saw the dash light. More later.

[Dr_Snooz]

I'm not sure that pulling the battery cable is a good idea. Good luck with the troubleshooting.

[lostforawhile]

dont pull the cable for testing a system with an alternator..........ever...........the battery being in the system helps stabilize the voltage, pulling the cable off with it running can spike the voltage to over 20 volts, possibly frying electronics in the car, and damaging the alternator diodes. in your case you probably have bad brushes or a bad regulator

[Buzo]

This chart is with the 1st "new" alternator. I drove like 10 miles round trip, for the time I got home the voltage was in 9V, and the max voltage was 12.8 at high speed and 11.3 (alternator light turning ON) at idle.

The root cause of my original alternator failure was brushes worn out. I bougth a rebuilt alt just because I was worried of the bearings to fail later in my old alternator, otherwhise I would change the brushes only.

I found the replacement alt was also defective.

I made my warranty valid and the 2nd alternator is "better" because the alt light is now gone, but when I turn the A/C on, the voltage drops below 13V, it didn't happen with my original alt though, so I don't know if my battery is going to get full charge.

I understand what you guys say about removing the battery cable. I think your concern applies to the old non-solid state voltage regulators. In solid state regulators as long as you keep the sense line and the output connected together when disconnecting the battery, there should be no problem.

[lostforawhile]

This chart is with the 1st "new" alternator. I drove like 10 miles round trip, for the time I got home the voltage was in 9V, and the max voltage was 12.8 at high speed and 11.3 (alternator light turning ON) at idle.

The root cause of my original alternator failure was brushes worn out. I bougth a rebuilt alt just because I was worried of the bearings to fail later in my old alternator, otherwhise I would change the brushes only.

I found the replacement alt was also defective.

I made my warranty valid and the 2nd alternator is "better" because the alt light is now gone, but when I turn the A/C on, the voltage drops below 13V, it didn't happen with my original alt though, so I don't know if my battery is going to get full charge.

I understand what you guys say about removing the battery cable. I think your concern applies to the old non-solid state voltage regulators. In solid state regulators as long as you keep the sense line and the output connected together when disconnecting the battery, there should be no problem.

that applies to any alternator, thats the worst thing you can do, never disconnect the cables on a running alternator. if you want to turn the alternator off, you can shut off the field wire, or on some Honda alternators, there is a field wire and a wire that carries 12 volts all the time, sometimes both need to be disconnected, this switches off the alternator without damage

[Dr_Snooz]

So many people are buying bad alternators. It really argues for rebuilding your own wherever possible.

[ecogabriel]

I found a shop that rebuilds alternators and starters south of ATL; they even do machining there.

Next time I have a problem I would head there. At the very least, I would have a bench test properly done.

[Buzo]

The second new alternator is not meeting my expectations.

The charging light in the dash is off all the time, but I see the voltage dropping below 11 V at idle and A/C ON. I checked my old logs and the voltage was at 13 V all the time with my original alternator.

It was a bad decision to buy a new alternator. Paid more than 100 USD for it, while the two brushes to fix the old one were less than 1 USD. There is no way I am going to get my money back so I will assume I bougth a very expensive set of bearings for future use.

If you have alternator problems, and unless your fields are burned, repair your old alternator.

[ecogabriel]

The second new alternator is not meeting my expectations.

The charging light in the dash is off all the time, but I see the voltage dropping below 11 V at idle and A/C ON. I checked my old logs and the voltage was at 13 V all the time with my original alternator.

It was a bad decision to buy a new alternator. Paid more than 100 USD for it, while the two brushes to fix the old one were less than 1 USD. There is no way I am going to get my money back so I will assume I bougth a very expensive set of bearings for future use.

If you have alternator problems, and unless your fields are burned, repair your old alternator.

I believe alternator bearings are not that expensive; perhaps replacement is not that easy (I never did it myself)

My civic is still running on the OE alternator I believe; certainly it is not a reman. If I remember right, lost said that the 5/6gen Civic would fit the 3g... maybe go fishing for an alt next time i go to the jy...

[lostforawhile]

The second new alternator is not meeting my expectations.

The charging light in the dash is off all the time, but I see the voltage dropping below 11 V at idle and A/C ON. I checked my old logs and the voltage was at 13 V all the time with my original alternator.

It was a bad decision to buy a new alternator. Paid more than 100 USD for it, while the two brushes to fix the old one were less than 1 USD. There is no way I am going to get my money back so I will assume I bougth a very expensive set of bearings for future use.

If you have alternator problems, and unless your fields are burned, repair your old alternator.

I cant do it right now, but I might be interested in buying that one from you, at least it wont be a total loss, I have a spare good carb regulator and extra brushes, so I can fix it, i have a dual alternator setup, civic one and a factory one for backup they can be switched back and forth

[Dr_Snooz]

I will assume I bougth a very expensive set of bearings for future use.

What, you think they replaced the bearings but not the brushes? The only "rebuilding" that alternator got was some light cleaning and a couple new stickers. If you got it from a corporate parts store, consider it a shiny clean core. You can get decent parts from those stores, but you have to special order them by name.

[Buzo]

A couple of charts more to document what everybody already knew.

I changed the brushes in my OEM / original alternator and put it in the car. I got 13.1 volts at idle regardless of the load.

And for reference the left chart is the autozone, shinny, useless alternator with 11.6 V at idle.

I wish these charts were helpful to get my money back...

[Buzo]

I cant do it right now, but I might be interested in buying that one from you, at least it wont be a total loss, I have a spare good carb regulator and extra brushes, so I can fix it, i have a dual alternator setup, civic one and a factory one for backup they can be switched back and forth

It would be really interesting to find what's wrong with these alternators from autozone. I'm sure it is not the regulator because the voltage rises with the rpm, I just never saw enough voltage out of the alternator to make a "flat" regulated output, I believe there must be an open field or something. I am going to try to talk with the manager and see if he understands about some electricity / customer satisfaction basics.

[lostforawhile]

It would be really interesting to find what's wrong with these alternators from autozone. I'm sure it is not the regulator because the voltage rises with the rpm, I just never saw enough voltage out of the alternator to make a "flat" regulated output, I believe there must be an open field or something. I am going to try to talk with the manager and see if he understands about some electricity / customer satisfaction basics.

it's very possible it's the regulator, the current output of the alternator is directly controlled by it, they use cheap junk regulators

[Dr_Snooz]

From what I've heard (from Lostforawhile, IIRC), they drive up to the rebuild plant with a dump truck full of cores and drop them in the middle of the floor. The rebuilders put the cores on a tester for about 5 seconds. Anything that lights up the tester gets painted and sold. These guys are probably getting paid piece rate, so there is absolutely zero incentive to spend any time making sure the alternators actually work. You partner with the plant as an unpaid member of their QC department. They appreciate that you volunteer your time and labor to help them test their alternators in real world conditions. LOL

[Hauntd ca3]

if anyone has any charging problems, save all the bs of going backwards and forwards to a shit hole parts warehouse and go and see an automotive electrician and get it done right the first time.
even if you take in just the altenator, an auto sparky will have a test bench that they can load it up with and test the max output.
a basic recon with brushes and bearings would cost you all of bout $100-120, and it WILL work.
even if it requires slip rings, that might add 20 or 30 bucks to the price.
i rebuilt mine, new stator,slip rings, brushes,bearings and rectifier for $250. the only thing thats factory are the rotor, the housings and pulley. plus i put in a 3 pin regulator to get rid of the fr terminal.
if i get a chance over the weekend i'll do a step by step dismantle and rebuild and post it up if anyone wants.

[Tdurr]

^^^ this. please do it.

[lostforawhile]

From what I've heard (from Lostforawhile, IIRC), they drive up to the rebuild plant with a dump truck full of cores and drop them in the middle of the floor. The rebuilders put the cores on a tester for about 5 seconds. Anything that lights up the tester gets painted and sold. These guys are probably getting paid piece rate, so there is absolutely zero incentive to spend any time making sure the alternators actually work. You partner with the plant as an unpaid member of their QC department. They appreciate that you volunteer your time and labor to help them test their alternators in real world conditions. LOL

pretty much it, I've taken failed "rebuilds" apart and found nasty dirty grease and crap on the inside, straight from the junkyard with a coat of paint