I go to the store in person and order them.
I've Got the No-Charge Blues
- Thread starter Gonzo
- Start date
Gonzo
Member
OK, I'll try that. Thanks.
Gonzo
Member
I was able to buy a VR706 from Autozone yesterday. They brought it in from another store. However, it does not resemble the picture posted by cbarge. Not metal but black plastic, without the option of using the original VR cover.
There are no part numbers or any kind of part ID on the unit. It just came in a box labeled VR706.
I installed it and it worked according to spec, so I'm happy about that. I hope that it continues to perform as described by cbarge.
There are no part numbers or any kind of part ID on the unit. It just came in a box labeled VR706.
I installed it and it worked according to spec, so I'm happy about that. I hope that it continues to perform as described by cbarge.
I don't see it mentioned yet...
You can have a 500amp alternator on a bone stock car and wiring and be perfectly fine.
An alternator only responds to the demands on the system, it doesn't give it's full output unless requested.
If your car is stock it's never going to ask for more than 40-50 amps.
You can have a 500amp alternator on a bone stock car and wiring and be perfectly fine.
An alternator only responds to the demands on the system, it doesn't give it's full output unless requested.
If your car is stock it's never going to ask for more than 40-50 amps.
Gonzo
Member
That should be the case here because it is stock, and what you say makes sense. But for some reason the new, but OEM design, points type VR I first wired up to the 90 amp Powermaster, failed with evidence of fried points. And the fact that manufacturers give amp limit recommendations (the FuryGT electronic VR that I impulsively ordered suggests no more than 60 amp alternator and mine is 90amp). So cbarge's success with the Autozone 706 electronic VR with the 90 amp alt and stock wiring is why I went that way instead of the FuryGT VR. I have no power demands beyond stock 67 Sport Fury with air conditioning.
What's a mystery to me is why the first one failed (It took around 600 miles). So I'm nervous about long term reliability with this VR 706.
What's a mystery to me is why the first one failed (It took around 600 miles). So I'm nervous about long term reliability with this VR 706.
rags
Senior Member
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.
Those are good questions.
From everything I've read, a charging rate of over 30 amps to a lead acid battery does nothing except create heat within the battery. That can cause all sorts of issues, like boiling the electrolite or bulging the sides of the battery.
The #14 fusible link in the stock charging can only pass about 34 amps before it fries.
So, I'm not sure of the answer.
That said, IMHO, most of the high amp alternators are a waste of money. Unless you have some high draw electrical stuff like some killer amplifiers or maybe EFI, there's no way you'll need that much charging. But the guys drink the Kool-Aid and figure "bigger is better" when really, that larger alternator isn't needed, might be causing more problems, and of course, takes more power to turn. I've read that every 25 amps takes about 1 horsepower, so a 100 amp alternator takes 4HP. I've known people to spend hours and $$ just to get a 2 HP gain, and here you are throwing it away.
But the magazines, in their desire to sell crap you don't need, tell you "this is today's trick setup" and "You aren't a man if your alternator isn't as big as the one Tesla used at Niagara Falls". OK, maybe not the last one....
But it's like the talk of "how many amps is the regulator good for" and you see 60 amps, when in reality the field only draws 4 or 5 amps. The rating may be taking the output of the alternator into account, but I can see by reading different threads, that people actually believe that 60 amps is flowing through the regulator. That's not to say that a regulator doesn't need to be able to carry more current when you put a larger alternator in... It does.. Only just a couple amps more. Just everyone really isn't understanding how it all works. The charging current doesn't flow through the regulator. Those #18 wires to the field connections will tell you the field doesn't draw that much.
Gonzo
Member
What a swamp!
rags
Senior Member
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.
thinking about this stuff helps us keep the alzheimers at bay.
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.
One thing... In a revolving field alternator, which is what we have, the armature is fixed while the field revolves inside it.
I found this a while ago and thought it was interesting. Note the higher amperage VR has a pot on it to adjust!
rags
Senior Member
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.
You're right... That would create a lower draw. I wasn't thinking about that.
Gonzo
Member
I'm impressed with the knowledge of electric theory by members of this forum. For me it's sort of like walking in on a graduate class while looking for electricity 101. Not to say I am a stranger to confusion.
The good news is the VR706 from Autozone continues to work very well after a couple of hundred miles. In fact Rosie is running better than ever.
Now back to the oil leaks............
Thanks for all the input.
The good news is the VR706 from Autozone continues to work very well after a couple of hundred miles. In fact Rosie is running better than ever.
Now back to the oil leaks............
Thanks for all the input.
5star1369
New Member
I 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.
Happy hunting
Joe
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.
Happy hunting
Joe
Gonzo
Member
Hey Joe
That's good advice. I have come to realize that the first place to look when having electrical problems is grounding. I just went through all that with my motorcycle. It was the ground, so I ran another heavier gauge ground wire from battery to frame. Problem solved!
So far, I am happy to report, Rosie (Fury) is performing as expected.
Thanks for your feedback.
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