i called autozone for an alternator price and he named of different amps like 35 75 and 90 and i asked if i didnt have a 90, if i could use it anyway and he said probably not, might burn something up...is this true?

 

The amperage rating of an alternator refers to how much current it can safely supply. Theoretically, a 90 amp alternator is capable of outputting 90 amps without burning itself up, if the regulator calls upon it. If, for example, you have a 75 amp alternator and you're not having any problems, a 90 amp alternator is a waste of money because the added power is never used. A 90 amp alternator doesn't pump 90 amps of current continuously; alternator output is a function of the system voltage, as determined by the voltage regulator. If the voltage is sagging, the regulator turns on the field and lets the alternator produce current. If the voltage is too high, the regulator shuts off the field and the alternator doesn't do anything. It's a back-and-forth process that keeps the system around 13-14 volts. It regulates the voltage, hence the name.

Your question was whether or not this will "burn something up." This depends. If you have a lower rated alternator now and it's enough to handle your electrical loads, and you install a 90 amp alternator, nothing will change. The alternator will only have to work as hard as the lower rated one did and you will see no difference. However, if you install a higher-rated alternator and you also increase your loads (you install a winch, an amp, etc), then I guess it's possible you could burn up the alternator harness if the gauge is not thick enough. But, if I remember correctly, I do believe that harness comes with fusible links, and if that's the case then you'll know if it's too much when the links melt.

But if all you're asking is can you replace your current alternator with a higher-rated version and you weren't having problems before with a lower-rated alternator, then no, it's not going to burn something up. The parts clerk doesn't know what he's talking about. But, I'm also telling you that it's a waste of money. People say "more is better" but I say only buy more when you need it, because the regulator will keep the alternator from supplying any of that extra current that's available to begin with. It's like putting 93 octane in your gas tank when you only need 87.

 

alright thanks....i thought it might help if i put in a newer radio or elec. mirrors and just wanted to make sure.....how do i tell what i have now?

 

Changing the radio won't really place too much added load on your alternator, so you should be good there. I think power mirrors should be okay as well. I'm sorry but I have no idea how to verify the amp rating of an alternator. I've always been curious of this myself too. I'd imagine the part number would tell what it is for an original one. The trouble is that even though a lot of alternators say Motorcraft and look original, they're actually remanufactured, and may or may not have been built to the same current rating.

 

alright thanks for all of your help.....

 

has anyone ran anything like this?

http://www.performancedistributors.c...ators-ford.htm