So I accidentally hooked a battery up backwards (yeah, I know, I'm a dumbass) and now when I'm at high rpms my volt gauge goes up to 15-16V...

I assume I've fried the voltage regulator in the alternator? are these replaceable? or do I need to just get a new alternator...

 

The stock gauges are not accurate, best thing to do would be to take the alternator off (5 minute job) and take it so.ewhere to get tested

Also, yes, they are internally regulated, so unless you want to take it apart, buy a new one

 

I've had a bad battery cause overcharging.

 

If you had a spare alternator with good electronics, you could gut it for the voltage regulator (and diodes), but it's not just a drop-in replacement; you'd have to fire-up the soldering iron. By far the easiest solution is to procure another 3rd gen alternator, or just revert back to a the S5 alt.

That said, I've never replaced the guts personally, so someone with hand-on experience might have more details.

 

I just had mine apart, the haynes manual makes it look like quite an easy job. I am however, handy with electronics.

 

Yes, don't trust the voltmeter in the car. Mine reads low, yours may read high.

I'd at least test with a voltmeter, or as was said, better take it to be tested.

Get a reman. one from a reputable mfr. if needed. You'll get a nice shiny one with new regulator, bearings and all. Just IMHO.

 

I took the alt. to advance auto and they said it was fine...

so either they don't know what they're doing (most probable) or my gauge went wonky (less probable).

Time to test it on the car with a multi-meter while someone revs the engine to 7k haha

 

Having an alternator is a bit of a crap shoot.

 

I'd say the voltmeter is accurate enough, provided every connection between the fuse box and gauge is in proper order. If it's saying 15-16v, your alternator's voltage regulator is trashed.

I've had a few alternators tested at the local parts stores and the procedure is damn near impossible to screw up. Input the ID number after identifying the alternator (customer tells you what car it's from), then wire it up using the supplied pigtail and diagram and push the "go" button.

Considering the hit-or-miss (and mostly miss) nature of 'remanufactured' alternators, now would be an excellent time to switch to a Taurus Alternator. Their output is tough to beat and the voltage regulator is accessible from the outside with 4 torx screws.

And the best part is you'll spend a tenth of what you would for a new FD alternator because 92-95 Tauruses/Sables/Continentals/Windstars are stupid common in junkyards. And yes, it uses the same pulley as a FD Alternator retrofit too

 

I just threw it back in the car and now everything is reading 14.1v rock solid while holding high revs in the garage.... *not amused*

 

14V on your dash voltmeter or on an external VOM?

 

On my megasquirt.

 

Just wondering if you perhaps fried the resistor in your dash voltmeter.

 

It was fine too, it didn't move from the 14V line...