Alternator Woes

[xpertsoldier]

Good Morning and in advance thank you for your help. I am totally lost and screwed right now

On Friday my alternator died no doubt about it. I took it to O'rielly's they tested it to be bad and gave me a new one as I have lifetime warranty with it. I put the new one in they gave me and the alternator is basically dead. It isn't running the car or charging the battery.

I have read countless forms and they say about the "Alternator/Generator Relay" or the light on the dash. Well the battery light on the dash comes on and for kicks I went and got a new Relay and put it in $44.00 later. Same thing

I Even out of frustration bought another alt for Autozone and put it in. Same exact thing. What are the odds I got 2 bad alts? They appear to have similiar markings so maybe from the same company.

I checked the voltage coming from the two cables going onto the alt and I have 12.63v same as what I have at the battery.

Please help I am totally lost and don't know what to do from here

 

[1990TSIAWDTALON]

Check all fuses under the hood? Alternator fuse/relay? My car is older but takes a 80 - 100 amp fuse. Just asking if you checked, its a good place to start.

 

[xpertsoldier]

I did check that 100 fuser in the fuse box in the hood. It looked good but I put a brand new one in just in case

 

[1990TSIAWDTALON]

Started car and checked voltage output of alternator?? Before it will charge it needs the field excited in the alternator. It takes 12v to excite it and is usually wired in with a dash bulb. You would see 12v when the car is in the on position on one of the other wires, not the main one(s) on the big lug on the alternator, it would be on one of the wires on the plug in. Since my car is older, I cant be sure which one but a voltmeter would check for voltage on one of the wires in the plug with the car in the on position. If your light goes out when you start your car, then that circuit is working. If it stays on then we have to diagnose more. If I knew which wire, I would tell you to jump 12 volts to that terminal and see if it starts charging. Thats what I do with my Chevy's but don't want you to burn out another so unless I know which one, don't try that.

 

[redgsxwing]

Have you had the battery load tested? Maybe battery is dying.

 

[1sick_gst]

Have you had the battery load tested? Maybe battery is dying.

This Did you have to jump the car to start it? Or did the battery have enough juice to start on its own?

 

[xpertsoldier]

I used a battery charger overnight to make sure the battery was at 100%. I was able to start the car right up with no problem. I also had the battery load test by O'riellys the day before and the test came back good also.

Also to mention when I put the key in the battery light comes on. When I start the car the battery light goes off. So it makes me believe that part of the circuit is good.

 

[Phantom DSM]

I used a battery charger overnight to make sure the battery was at 100%. I was able to start the car right up with no problem. I also had the battery load test by O'riellys the day before and the test came back good also.

Also to mention when I put the key in the battery light comes on. When I start the car the battery light goes off. So it makes me believe that part of the circuit is good.

If the battery light goes out once you start the car, does it eventually start flickering while your driving ?
If the alternators are good(even though i have seen plenty bad off the shelf) then it is time to check the ecu. On 2gs there is a driver called Qxx(i cannot recall exactly), these can go bad and does not not allow proper charging. The 2g has has 4 pin plug , you need to check with voltmeter with key on..ill try to find the thread with same issue and post it later.

 

[xpertsoldier]

If the battery light goes out once you start the car, does it eventually start flickering while your driving ?
If the alternators are good(even though i have seen plenty bad off the shelf) then it is time to check the ecu. On 2gs there is a driver called Qxx(i cannot recall exactly), these can go bad and does not not allow proper charging. The 2g has has 4 pin plug , you need to check with voltmeter with key on..ill try to find the thread with same issue and post it later.

Yesterday I had a shop look at it. They said it is either the alternator or ecu. On my way home the battery and brake light came back on about half way home. I was running on battery power and barely made it bacm

 

[1990TSIAWDTALON]

That usually points to a bad Alternator or blown fuse....or did on mine.

 

[xpertsoldier]

That usually points to a bad Alternator or blown fuse....or did on mine.

I am thinking the same but these wankers say the alternator checks out on their machine and are giving me hell about warranty

 

[T is for TURBO]

Try this:
Charge the battery, start the car, and rev it to 3,000 rpm. This manually excites the alternator. Alternator should start charging.

 

[1990TSIAWDTALON]

Check the alternator fuse under the hood with a ohm meter to be sure it is good. Do a conductivity check on it. It can look good but test bad.

 

[xpertsoldier]

I checked all of the fuses and everything checked out okay. I have around 12.63 I don't remember exactly at the alternator the b+.

I also have the same coming out of the four pin harness I believe the red cable. .when I turn the ignition on I had 11.63 or something out of the wire next to it and 5v at the last one

Check the alternator fuse under the hood with a ohm meter to be sure it is good. Do a conductivity check on it. It can look good but test bad.

 

[1990TSIAWDTALON]

Really should be getting 13.5ish out of the alternator. Do a load test. Start the car and turn on everything but the kitchen sink (lights, fans, stereo, etc) to load the alternator then test the voltage at the alternator lug. Should be more than 12 volts.

 

[xpertsoldier]

Really should be getting 13.5ish out of the alternator. Do a load test. Start the car and turn on everything but the kitchen sink (lights, fans, stereo, etc) to load the alternator then test the voltage at the alternator lug. Should be more than 12 volts.

I got oriellys to give me a new alt a bam it works. I am so relieved and pissed at the same time. Why did their alts pass when they were clearly defective

 

[1990TSIAWDTALON]

I don't think it loads an alternator hard but very glad you got it fixed!!!

 

[GRAVEDIGGER]

Why did their alts pass when they were clearly defective

Happens all the time... That's why I always tell people to test it on the car. If you don't have 13.5-14.8 volts with the engine running the alternator is BAD period. If you test it and it's only putting out 12.x volts, it's BAD.

 

[1990TSIAWDTALON]

Me to Matt. Best way to tell is just check it under full load at the alternator.

 

[xpertsoldier]

I really appreciate everyone and their help

 

[1990TSIAWDTALON]

Very welcome. I was the same way not to long ago and alot of people helped me from this site, so pay it forward when you can! Have a great day!