I picked up this car about a week ago it's had two new alternators and 2 different computers 2 different ELDs fuse 15 and the fuses under the hood all look great no matter what it's always the same result car will start and then run off the battery until it eventually gets to a point where it dies. Also the speedo dosent move Even had a friend who works as a honda tech come out with a fancy scanner and said everything read as it should no codes or system faults. Something else to note the battery light never comes on as it's dieing but it does light up for a moment when you turn the key on so I know the bulb is good. Any suggestions or help would be greatly appreciated.

 

Check the wiring to the alternators. I remember on an old beater car I had years ago, one wire came off the alternator and it died as I was driving but never displayed a battery idiot light or what not. I would suspect one of the many wires to the alternator has a break in it preventing the alternator from actually charging while everyhting seems to "check out okay".