So I am having this issue with the car and it is driving me nuts! I have done everything to my knowledge to try to fix it. Here is the stuff I have done.

*Removed alternator and tested at autozone 3 times in a row came back ok.
*Noticed a small leak was getting on it so while it was removed I cleaned the hell out of the terminals with every known electrical cleaner and used q-tips and all.
*Replaced both battery terminals
*Replaced battery

Now here is what happens. When the car first starts up it may or may not come in. It it is on I give it a little rev it shuts off and stays off. After driving or leaving running for about 30 minutes or so it somes back on BUT only at low RPMs. If I lay into it and bring it to about 3000+ RPMs it goes away but than turns back on when it goes to a lower/idle RPM. The alternator was replaced about 1 1/2 year ago and was a NAPA ReMan. Any help with this would be greatly appreciated

 

Directly behind the battery there are four ground wires mounted to the body of the car.The wires are white and all four are together, remove the battery and you will see them. Take the wires off and remove the paint to expose a better ground for them. I had similiar issues and bench tested at autozone with good results. My troubleshoot process went something like this, checked the wire running to the alternator, checked the ground running from the battery to the front of the motor, replaced battery, cleaned alternator posts, checked fuses under the hood and still nothing, but once I removed the four wires and exposed a better ground all was well. These problems also caused my 100amp alternator fuse to blow replaced that with a new one from the dealer. Report back with your results.

 

Did all that you said with no luck. Finally broke down and took alternator out. Had bench tested again this time saying it failed all the tests. Went to Napa to warranty it and they said they could not pull the record on it because last time it was done at a shop that is no longer in business. Against my better judgement due to my need for a vehicle I bought a autozone replacement alternator. Installed with fully charged battery and no light on. Have not driven yet so will keep you posted after a few days of driving to see if all is well.

 

If you keep having issues, please post back. I just had a really bad problem with my alternators testing good, and the car would start slow and eventually the battery would die. Turns out my car was running with 10ohms of resistance. I did "the big three" grounds and my car runs FANTASTIC! Ground-ignitor Ground-engine Ground-body. LMK if you need anything!

 

Is there any factors that would make the alternator give out 19 volts? My old one was doing that, so I replaced with an used one and it's doing the same thing now, could those ground connections be the culprit? (btw the alternator I just put in was tested at autozone and came out good)