Battery light came on and car died . Jump car pull battery cable car dies. Replaced alternator, battery light is out put car is not charging . Charge battery car starts but soon as you pull cable car dies. Another Volvo owner told me about an external regulator??? Any thoughts???

 

What year and model?

Generally if the car dies with cables removed the alternator is not charging. On some models that can be caused by other things than the alternator itself. And there is no external voltage regulator, other than the one bolted to the back of the alternator, that comes with a replacement alternator..

And don't ever disconnect the battery with the car running - you can damaged the alternator. Yes, that was a valid test when cars had generators - but alternators have diodes and stuff that can get damaged if the battery is not connected.

 

2000 s70 2.4L non turbo

 

1998 -2000 S/V/C 70s - Check the positive battery cable. A bad connection (high resistance) develops where the battery terminal is clamped onto the cable. When bad that terminal gets very hot and prevents the alternator from charging. Some people complain the starter is spinning slower or sounds different, or is hard to start. A new battery cable fixes the charging problems. (as long as your alternator is ok) To really test - do a voltage drop test, with your voltmeter connect one end to the alternator output (the big red wire) and the other lead to the POSITIVE battery cable. Does not make sense right? Voltage should be 0, it's positive to positive with the voltmeter leads. So - any voltage measured is the voltage drop. more than .5 volts is usually bad. Or if you don't have a voltmeter, connect a jumper wire directly from the alternator output to the positive battery terminal to bypass the poor connection in the cable to see if the alternator will charge then.

While there check the smaller red wires at the positive terminal. Those 4 wires all go to the same place - the 8mm nut (with the 13mm head) that feeds power to the fuse box under the hood. If you undo the nut and pull the wires up you will find them melted. Those won't have anything to do with the alternator charging - but causes problems with other systems (having low voltage there).