I think I am just very unlucky...low voltage issue.

[One Equals Two]

So guys, I am a newbie to DSM but not to cars. I think I am just very unlucky with this set of problems but think I have it down. Tell me if this sounds right to you and if it's a possibility.

So, I have a 98' GST, ran perfect the day I bought. Now it runs horribly, and it's a long story. Lots of pain, but no serious issues yet.

Anyway, long story short, I noticed that I was leaning out at the high end of boost. Then it got worse and I could tell it was running leaner and that the fuel pump was starving. I checked the voltage, and it was hovering around 12.9 volts. Not alarming by itself, but I realized that normally it would run 13.6 and above, so I figured my alternator was out. But to be safe, since I had a new battery laying around, I dropped it in the Eclipse to see if that helped, and it didn't.

So I replaced the alternator and my voltage plummeted. 11.8 was the highest it'd go, no increase with rpms. Also the baseline voltage dropped at this time, meaning the battery voltage was 11.1 volts at a stand still. I had put the original battery back in. After a lot grumbling I took the old alternator back and got a new one. (THAT WAS THE PROBLEM FOR THE NEW LOW VOLTAGE but...) Now, it's up to 12.8 volts but the battery voltage is still 11.1. It used to be 12.6 because the turbo timer even with the motor off still wouldn't blink warning. But now it screams at 11.1 volts.

So, I am wondering, did my battery manage to die right when I replaced the alternator? Therefore causing a whole hell of a lot of confusion. The car has signs of a dying battery but it was just fine right when I replaced the alternator, so, I am just wondering if my luck is that bad... Please tell me I am not crazy, or if it looks like I got another bad alternator.

P.S. When the car warms up, it drops to 12.2 volts running and barely stays running. Fuel pump is starving for sure, it sputters and the A/F ratio is like 20:1

 

[i_nick_2005_i]

Your alternator should be charging a constant ~14.0 volts when the car is running. If it's not, then it's a problem with either it or the wiring. I presume it is the alternator itself. Even with a completely dead battery once you started the car it would be charging ~14.0 volts. It is not the battery, it's the charging system.

 

[One Equals Two]

Simple question here (by the way thanks for the help): Does a bad alternator cause low voltage, even when the motor is off?

The radiator fans are wired to always be on, but I don't think that will drop it 1.5 volts.

Thanks i_nick..however, shouldn't my battery voltage read somewhere around 12.5 just as the battery? I know that the alternator should be mid 13's to 14, so, does that mean I have another bad alternator? Also, I got it at Autozone...and I hear that they are infamous for giving crap alternators.

I checked all the wiring, and I can't find anything. Redid all the grounds and pulled all the fuses, (one at a time) to trace down any shorts, but no change in voltage.\\

wow that sounds exactly like my issue.I hope we get some answers. Something is def draining my battery

Does your car still start just fine like the battery is getting charged? Mine does, and I've never not had it start. I forget to mention that I have done just about every single precautionary measure, or trouble shooting suggestion I can think of. Check grounds, fuses, wiring (for frayed wires), voltage at all places (always 12.5v with the car off), etc.

 

[NOSLO2PT0]

Replace the wiring from the alternator to the fusable link, then from the fusable link to the battery. Replace some ground wires.