Hi i new here. ok first info on van it a 1994 grand carravan eng 3.8 fwd everything power
ok here my problem i put a new alt not rebuilt a new battery and a engine computer
the problem i have is my volt on van had before this stuff i need to replace was 14.4 volts is now only 13.5 volts it goes down to 12.7-9 volts when turn on everything rearand front a/c , lights, radio , etc. but when nothing it stays at 13.3-4 volts but the van runs good with no problems no check engine light. i check the whole engine wire harness the alt one i retape it and loom it i don't see any burn wires. at this point im stuck don't know what to do has anybody had this problem or if anybody could help me with this problem. i already put 500 dollar in to the van and still have the same problem

Thanks in Advance Kingss