PrecisionAuto

The alt came from Napa, they use a computer tester that spins the alt up to 2200 rpm while measuring voltage and current across a load curve, they tested It correctly. the vehicle Is completely capable of running every accessory with out the battery connected with and damage to any part of the vehicles electrical system. the whole story about how alts work was cute, but still dose not explain why the vehicle will die If left running @ Idle. all wires at the alt have the correct trigger voltages to activate the alt. actual voltages were In the neighbor hood of 12.26 - 12.48 volts dropping the longer the vehicle runs until It dives out and stalls at about 9 volts. at this point I reset ( disconnect the batt for 10 min) and charge the battery back up with a brand new snap on logic charger. It seems to be something such as Idle speed...

I tested voltages running and off, and running with battery terminals off . same results every time, 12 volts, I tested all the wires in the 3 pin harness @ the alt and all 3 are at the same voltage 12 volts. there is a new belt and tension pulley. the battery is in top condition passing a draw test and hydrometer reading so all your basics are covered any other bright ideas

I replaced the alt twIce on a hunch I may of recived a faulty one, but I stIll have the same no charge condition. I looked at wire harness connectIons and I Inspected the wIres all seems good no dry rot plastIc or wIre Insalator nothIng Is chafed or burnt rIpped or torn. I'm perplexed

Hello all, I am working with a 95 LS 400 that is not charging. I have replaced the alt and checked all fuses, links and wireing harnesses, but still she will not charge. any ideas are greatly appreciated