Originally Posted by articfriends

Depends on the kind of alternator, I learned ALOT about alternators this spring that I NEVER new even after years of building cars/boats/hot rods etc. I doubt you have any wires backwards or batterys would go dead/blow up, burn wires off etc. We built a efi 1974 Transam, used a 10si 140 amp powermaster altenator because it has about 60 or so amps off draw and a optima red top battery, alternator would get to about 275 to 350 degrees when everything was running and then quit working. Had it waaranteed, same thing happened, put snap on amp clamp on and car drew between 40 to 80 amps, even more if you ran fans with car off, 10si is like a old gm alternator from 70s. It had a external fan, they can rate it at anything they want but only having a external fan it could/would NEVER support the amperage it was rated for, not even half, for very long without cooking. years ago I upgraded my alternator on my Baja to some 100+ amp one, boat had all kinds of electrical draw and is about 12years old. Took a hard look at it and see it has a external fan AND a built in internal fan, after cooking 3 alternators and incessantly pissing around with this car going dead everywehere I switched to a cs 130 style which has a external AND internal fan, havent had a single problem since then. Also keep a few things in mind, creating wattage/making aperage creates heat, their is a direct correlation, the more load there is the more heat it puts out. In my case optima red top, I read ALOT about these baterrys that I also didnt know, IF they get run down, unlike a lead acid cell batttery they will draw what ever the max output of your charging system is until pretty much fully charged, so in my case when we ran fans on car at chassis dyno it lowered the surface voltage, when we started it the alternator was maxed out at 100% for quite a while, and burned up on way home, people in the know say to ALWAYS top off optima batterys if they get run down with a charger NOT your charging sytem. In your case has anything changed from before, extra load on charging system? Has alternator actually failed and quit charging? If not I would probably just stay away from it to not get burned and leave well enough alone, Smitty

Originally Posted by ICDEDPPL

I`ve never noticed either of mine to be as hot as you describe full charge or not. One of mine charges a starting and house battery