anybody have any tips on identifying a heavy duty altenator. i have an 84 f250 300 six. about 3 years ago i had the altenator serviced and was told that it was a real light duty model. how can i identify a heavier duty model from the auto wreckers ? any tips?

richard.

 

https://www.ford-trucks.com/dcforum/User_files/mil1ion/3bd799a0409456e9.gif
Until you get higher than 55-60 amps.
The smaller ones look a like.

After that it's SIZE.
You should be able to tell.
Another tell tale clue is How many options has(or Had) the truck on it.
Most times (loaded trucks had bigger alternators)


Dennis

78 F-150 429CJ 465,000 KM.(Original Owner)
68 Mustang 289 Sunlit Gold 80,000 Miles(second Owner)
64 1/2,260 Pre-World's Fair Mustang #8092
64 Fairlane 500 S/C,waiting for a 390 4-Spd

If The Girls Don't Find You Handsome,
They Should At Least Find You Handy!

 

near the main mounting hole boss (the thru bolt boss) there is a stamping that states the voltage and amperage of the alternator. example 12v 65A, also there are 3 main types of ford alt the most common being the rear terminal 40-100 amps all conections are on the back of the case, very cheap used for about 25 years, common and reliable.
The side terminal which is very rare and hard to find not to mention expensive only available as 85 and 100 amp versions "I believe" the case on this alt is huge and has a totally different mounting brackets than the common rear terminal alt THEY CANNOT BE INTERCHANGED WITHOUT MAJOR MODIFICATION
And the internal regulator alt used from 86 and up 100 and 130 amp only "I believe" , same basic design as a rear terminal alt but with int regulator, not recomended to replace the rear terminal alt as they both do the same thing but the rear terminal alt does it cheaper and just as good