World Famous Barge in a Budget
FCBO Gold Member
- Nov 22, 2010
- Reaction score
- Kingston Ontario Eh?
Those are good questions.and if the car is jump started with the battery stone dead? or if the battery has a shorted cell? or if jump starting another vehicle? got to be careful with these things.
you make a good point about the fusible breaking to isolate the potential battery overloads to the system, but then what does that 500 amp alternator do the system when the battery becomes disconnected. i suppose the voltage will spike through the roof for a moment then settle back down. i wondered about the higher capacity regulator myself for the same reasons. the armature must draw a higher load but why? the larger alternator uses more horsepower so greater magnetic forces in opposition. some horsepower goes to the larger rotating mass, but the higher electromagnetic force has to come from somewhere. that's the higher load from the field to the regulator.Those are good questions.
thinking about this stuff helps us keep the alzheimers at bay.What a swamp!
The wiring for the field is longer in the higher amp alternators so you can have more turns around the core to increase the magnetism, so the resistance would be higher. At least that's how I understand it.i wondered about the higher capacity regulator myself for the same reasons. the armature must draw a higher load but why?
exactly what i wondered about. the winding would be longer so higher resistance. higher resistance would create a lower draw. a long circuit vs a short circuit. thinking maybe they use a lower gauge wire? watching the video, the load is checked with the power supply set to 14v. that's "full fielding" the armature. makes a good point for the demonstration but is a little deceptive. learned from it that a person could easily check the requirement of their alternator by using a similar set up. it could be done in the vehicle. the car battery to the field and an inductive ammeter. note also that the resistance of the two armatures were not checked so we don't actually know their respective differences.more turns around the core to increase the magnetism, so the resistance would be higher. At least that's how I understand it.
You're right... That would create a lower draw. I wasn't thinking about that.exactly what i wondered about. the winding would be longer so higher resistance. higher resistance would create a lower draw. a long circuit vs a short circuit. thinking maybe they use a lower gauge wire?
Hey JoeI just had a similar situation on my stepson's 68 Sport Fury. It charged when it wanted to. This is not a show car by any stretch of the word, it is a daily driver. I did the bypass, as we were losing over 1 volt from the alternator to the battery. That helped for about a week, then it just stopped charging. I full fielded it for a minute, and still no charge. Took the alternator loose and checked the field terminal, and the ground terminal ( still has single field alternator with a parts house regulator and the original cover). The problem ended up being fixed by adding a ground strap from the alternator to the block. It wasn't grounding well through the case. I did clean up the little bits of corrosion and it started working, but I felt safer adding a dedicated ground.
This may or may not have any bearing on the issue you are having, but just taking it loose and putting it back on can affect how it grounds and make a good enough connection.
As always, free advice is worth just what you paid for it, and YMMV.