2004 GMC Envoy • 6 cylinder 4WD • 127,000 miles

I have been having to jump my car lately every couple days the alternator is fine and when I jump it the dash board goes crazy on me flashing all check engine lites 4wd abs ect as well as my spedomiter and gas and oil presser gages not working I pluged in a diagnostic machine and got no code it drives and runs but cant figure out the problem I also looked for a loos groung and possibly blown fuse and nothing. Please help its driving me nuts thank you
February 27, 2014.

Please use some punctuation, otherwise that huge sentence can be misread a number of ways. What does "nothing" mean"? Nothing works? Nothing is wrong? How did you determine the generator is okay? Did you have it tested with a professional load tester? If so, what were the results for output current? How old is the battery?

Feb 27, 2014.