I had the same problem and it was the voltage regulator. But I spent 100 buck on the lamp charge relay first which didnt do sh*t. The voltage regulator is under the hood on the driverside fender and is real easy to replace but buy a good one I went throught 2 kragen ones. Or... have your alternator rebuilt with a internal voltage regulator and they can bump up the amps at the same time! Thats what I ended up doing and am very happy. your lamp charge relay is in the cab under the dash on the door side of your passangers feet. It is a little gray box bolted to the sheetmetal under there. Hope that helps but sounds like a charging issue and not a relay issue. If it is the relay I have one you can have, but I highly doubt it.
