jcjmw

Car was running fine, power good, no issues. Then, about 3 weeks ago, I got the red alternator/battery warning. I charged up both batteries, just to make sure it was not the batteries. Same thing, red alternator / battery warning. This time I also got a random misfire cel, and misfire on cyl 5, 7 and 8. I changed out the O2 sensor. My Indy shop put in a replacement alternator (it was $350 Bosch part; not know if it was rebuilt or new), with a replacement voltage regulator. I also had the radiator fan replaced with oem new fan since plastic blades around old one cracked causing some fan imbalance.

After replacement alternator, at WOT, the voltage drops to 11.4, causing red battery warning (but not the red alternator warning) and accessories shut off and the same prior random misfire cel.

In D, with ac on, radio on, voltage is 13.3. If I just sit / car not moving, voltage slowly drops to 11.8. When car is moving, it will then get to 13.3 but after about 2-3 mins of constant driving (originally, right after alternator change, max voltage was 13.9, with ac on. Now, after 2 days, max voltage is 13.3. I changed out the battery control module, aux battery relay and accessory belt. Both batteries are in great shape (battery charged shows both at 100% voltage). After all of that, same problem - no change.

I am thinking the replacement alternator is the problem? I have Star. Is there a way to use Star to help me find the cause/solution?

Anyone else ever encounter this problem?

lost_wave770

How old are the batteries? Because you have basically replaced the entire charging system. Batteries do not last forever. Also a dead battery cell or one that is about to die tends to show full voltage, but your amperage will either leak or not be there.

StarvingArtist

That random misfire sounds familiar, I don't remember what the problem was or who had it, but check your fuel pump. Look for burnt wires.

Yacht Master

Alt is junk @13.3V. and just replace your batteries if they are older than 3 yrs.

jcjmw

Batteries are both at 3 year mark (I think). But, is the alternator bad and that is the problem? Or is it the batteries?

Thanks.

jmb614

If the alternator was good I would think you would see more than 13.3 at the battery terminals, but I'm no expert on the electronics of this car.

justinreinke

You ever figure this out I am having similar issues? Voltage weak with a new alternator, voltage regulator and rear battery. Red battery light and convenience features warning comes on when I get on it. Used to be just WOT but has gotten worse. I was stranded and my alternator melted so I had to replace with a reman. Took the car in and they said it was voltage regulator which I had replaced with a bosch unit about an hour before. I am pretty sure I do not have 2 bad regulators. I am guessing the reman alternator is crap but if it could be something else I would love to know. Had the small battery checked outside of the car and it was fine.

kponti

Reman alternator is crapped. I bought a "Bosch" reman from Oreilly once, had to take it back and buy it from the dealer a week later. Under WOT it will pretty much stop charging

jmb614

So the Bosch AL0826X Remanufactured Alternator is what gave you problems? Anyone else have experience with this part?

O-55

If you end up needing an alternator, get yourself a Bosch AL0826N from a retailer. It will be less expensive than what the dealer will sell it to you for, and usually less expensive than a remanufactured unit.

kponti

Honestly not sure what the part number was , but I do know that it lasted a week in my car and I removed it

justinreinke

For me, I just pulled my O'Riley's reman alternator and the will not exchange it for me because it tested good. Can't get a refund either. Tempted to buy a new bosch but will be upset if I have have the same issue. Anything else it could be? Would a BCM cause the voltage to be low and go totally ape under heavier acceleration? The little battery tested fine and is only a couple of years old. Maybe that but I really have a feeling it is this reman alternator.

justinreinke

Considering Kponti seemed to have similar issues I am getting O'Rileys to refund me after all and I bought a new Bosch alternator off Amazon. Hopefully it is just an inferior alternator that tests good.

Is AL0826N is the right part number or is AL0826X the right part number? I ordered AL0826N and now I am questioning that I ordered the right one.

kponti

My Oreilly alternator tested good off the car, I even switched out the voltage regulator and it tested good as well off the car.
After I installed however it tested low on the car

jcjmw

I thought I would update. For me, it was the alternator. The original replacement alternator was a refurbished Bosch unit, with a new voltage regulator. They confirmed it was bad. It was replaced with another refurbished Bosch unit, with a new voltage regulator, with the same 2 year warranty. All is good now. I paid $0 for this recent warranty replacement.

O-55

It's the correct part. The "X" signifies that the part is remanufactured. The "N" is an all new unit.

Here it is on my car.

Max.H

any updates on the voltage drop? Hope you got it fixed!

jcjmw

Yes, a replacement alternator solved the problem.

Max.H

Nice

justinreinke

FWIW I thought I should come back on and say a new Bosch AL0826N alternator completely solved my problems even though the parts store alternator tested good on and off the car.