My alt is dying, looking at some online through a ford dealer and they have like 4 difference kinds... dual alt, 140 amp, 110 amp, 120 amp. I have no idea which one to get. They're all pretty similarly priced.

http://www.tousleyfordparts.com/part...ion=ALTERNATOR

 

Call either the dealer or an Oriellys and give them your vin and they should be able to tell you which one you need.

 

They all fit my truck.

 

You can't have to much as amperage. Just get the highest one if they all fit right imho. It has a regulator.

 

Get the one that is a perfect match. You may have to get the number off the alternator and have them (parts stores) give you the correct one. If you are trying to order online, take your number, Google it for an interchange, and then use the correct match. You can't always just go to higher alternators. Some are bigger around and won't fit the brackets, others have different rotation, etc. You want to match it correctly, then you can go to their (who ever you are buying from) and look in their buyers guide for the correct picture and information. You can look at the other numbers this way also, and compare them for looks and if they will fit. Hope that helps.

 

I thought you had an F150. These are all for SuperDuty's with 6.0 l engines. You definitely will have to get the number off a SD to match correctly because of options.

 

oops