Taurus electrical issues

Car started losing electrical power on the way home from work last week. Dim lights, blower stopped, wipers stop, almost stalled out when getting off the interstate. Barely made it home. 30 minutes later went out to troubleshoot and it started right up. Ran for about 2 minutes and stalled out from lack of electricity. Put voltmeter to alternator and it seemed to only be putting out 8.5v. Took to store to have tested. Replaced alternator and it didn’t help. Reman alternator still seemed to only be putting out 8.5v or so. Checked fuses and cleaned battery terminal and verified good block ground and good body ground. Still having problem. 1996 Taurus. Any ideas on what next? Battery is exactly 2 yrs old and was putting out 11.6 when the problem first started last week. Due to cold and this existing issue, battery is only at 6.5v right now. Can jump the car, but then after removing jumper cables car dies in 30 seconds. Should I have the battery tested? What else could/should I be looking at?

Did the replacement alternator come with the voltage regulator/brush set installed? The Motorcraft alternators that I installed in the past did not.

You should recharge that battery before starting the engine, the load of a discharged battery can overheat and damage a new or reman. alternator in 5 minutes.

It seems to me that the 1989 Mercury Sable we once owned had a voltage regulator that was not built into the alternator and I think I had to replace the voltage regulator once. I don"t know if your later model aTaurus has the same setup. If so, the regulator is a suspect.

@Nevada_545 , Did the parts you mentioned fit into the alternator but had to be purchased separately or was it an external regulator like older vehicles had ? Since you mentioned brushes I assume those parts had to be installed into the alternator itself . I once had a 78 Ford van that had an external regulator .

Check the fusible link(s)

I believe this particular Taurus has the regulator built into the alternator. It’s also quite possible the “new” alternator . . . probably a remanned unit, by the way . . . is defective. Not uncommon

@Sloepoke They were internal regulators sold separately, I believe the parts came from the Ford dealer. I just looked at new and remanufactured alternators online and all seem to come with the regulator now so it doesn’t seem to be a possibility.

The new voltage regulator/brush assembly only takes a minute to install in the back of the alternator, note that the blue pin must be removed to release the brushes;

Make sure that the battery warning light turns on when you turn on the ignition. It supplies power to the exciter inside that alternator (it ties to the ‘L’ lead of the alternator). I learned about that the hard way many years ago when I couldn’t figure out why the charging system on a Ford pickup wouldn’t work. The bulb socket was dirty and current couldn’t flow through the bulb filament. Whenever the charging system doesn’t work that is the first thing to check.

Are the cables clean and not corroded up? Is the ground connection to the engine and chassis clean and rust free? Are the cables original OEM cables? Did someone stick one of the aftermarket battery connectors on the battery cables?

Are you testing the running voltage at the battery or at the back of the alternator? I’m wondering if you have a failed fusible link between the battery and alternator.

Does the dashboard battery light illuminate when the key is turned on? If not, that can prevent the alternator from charging.