'99 Windstar alternator amperage ratings

[thomastidewater]

Just a quick question. My '99 Windstar LX 3.8L has begun making a fairly quiet for now, high pitched, steady squealing noise that I noticed while idling at a drive-thru where the sound echoed off the restaurant wall and back to my ears. I realize this might be due to many different causes, but if this turns out to be the alternator beginning to fail, which amperage rating for a new alternator will I need? When I shopped around online to see what new alternators cost, I noticed they come in either 110 amp or 135 amp ratings for the Windstar (I even saw some 130 amp rated alternators, which I assume are similar to the 135 amp models). Does it matter which one I buy? 110 amp or 135 amp? I would think that 110 amps would maybe be gentler on my Windstar's electrical system, but I'm not sure. Any thoughts?

[tomj76]

Amperage is how much current the alternator CAN deliver if the electrical demand requires. However, the fuses in the system will limit how much current can be drawn even if the alternator is capable of producing more.

Consequently it will not hurt to have an alternator that is capable of higher current, but it might not help either, and in fact it could be a waste of money to install a high output alternator.

I read somewhere that the OEM part is a rated for 110A, so that is probably all you need, but it won't be any gentler on the system than higher rated current replacement.

[12Ounce]

Size matters! As noted ... the alternator output will not exceed the demand, but the larger rating is an indication of heat dissipation capacity. All good!

[thomastidewater]

Thanks tomj76 and 12Ounce! Now I understand.