Alternator?
Honestly I don't know why you would change alternators if the factory one is still in good condition.
If you want to have a replacement one on hand, OK. Although a replacement isn't so rare that a parts store can't get one in that day, at most within two or three.
Since things are apart right now, you can do some basic checks of the alternator on the bench. Then when everything is together, you can check the stereo draw - but you're saying its pretty small unit.
One problem with replacement vs. factory is they aren't measured and rated the same way.
The only way to know the tuth about max output will be if/when someone tests an original at different rpms and loads.
That is also true for any 'replacement' unit, and we could measure it holding the same voltage as the factory unit tested.
Occassionaly a test sheet will show up in the box with a replacement unit. I think this was the general practice of a particular big rebuilder maybe 10-20 years ago. These things sit on the shelf in a warehouse so once in a while show up.
Here is themax output plot from the only mopar one I've seen.
This is was in box with '78amp' revised squareback.
The rpm is Alternator rpm, not crank rpm.
Notice at the top it says the test was done at 13.2 Volts.
The factory service manual test is done at 15 Volts.
If this replacement alternator had been tested at 15 Volts, the Amps out at all rpms would probably be less.
But the main point is that the 'rating' doesn't tell us alot unless we were comparing all from the same manufacturer.
A few years ago A/C Delco or delco-remy had output graphs for some of their GM alternators. Notice that sometimes a higher rated alternator has worse performance at low rpm.
We don't have this type of info for the Chrysler roundbacks and squarebacks alternators so its all a big maybe when we buy replacement. On top of this, we can't be sure the parts between different alternators weren't mixed, or that any new parts installed had any sort of quality control.
Honestly I don't know why you would change alternators if the factory one is still in good condition.
If you want to have a replacement one on hand, OK. Although a replacement isn't so rare that a parts store can't get one in that day, at most within two or three.
Since things are apart right now, you can do some basic checks of the alternator on the bench. Then when everything is together, you can check the stereo draw - but you're saying its pretty small unit.
One problem with replacement vs. factory is they aren't measured and rated the same way.
The only way to know the tuth about max output will be if/when someone tests an original at different rpms and loads.
That is also true for any 'replacement' unit, and we could measure it holding the same voltage as the factory unit tested.
Occassionaly a test sheet will show up in the box with a replacement unit. I think this was the general practice of a particular big rebuilder maybe 10-20 years ago. These things sit on the shelf in a warehouse so once in a while show up.
Here is themax output plot from the only mopar one I've seen.
This is was in box with '78amp' revised squareback.
The rpm is Alternator rpm, not crank rpm.
Notice at the top it says the test was done at 13.2 Volts.
The factory service manual test is done at 15 Volts.
If this replacement alternator had been tested at 15 Volts, the Amps out at all rpms would probably be less.
But the main point is that the 'rating' doesn't tell us alot unless we were comparing all from the same manufacturer.
A few years ago A/C Delco or delco-remy had output graphs for some of their GM alternators. Notice that sometimes a higher rated alternator has worse performance at low rpm.
We don't have this type of info for the Chrysler roundbacks and squarebacks alternators so its all a big maybe when we buy replacement. On top of this, we can't be sure the parts between different alternators weren't mixed, or that any new parts installed had any sort of quality control.
