Alternator/charging questions

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furyus2

furyus2

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Hello,I need some help from the electrical guys on this site. I'm using this site instead of the B body forum because I know there are some really smart guys here. The car is a 64 Sport fury. It has a 440,and I converted it from the old style alternator and regulator to the square back alt and flat style reg. I have msd ignition,with no ballast resistor. There is no radio or electric fuel pumps or fans
What's happening is when I did the conversion it worked great. Then I came across a chrome alt that was supposed to be rebuilt and it worked great for a while,then it started to not charge (less than 12 volts) at under 1000 rpm. Above that it worked fine. So I took it to an alternator shop and he said the diodes were bad,and fixed them as well as press on a billet pulley from my March kit. Put it on and it worked ok for awhile then it would do the same thing,not charging at less than 1000 rpm. So I took apart the good (not chrome) alt. and put the stator and the diodes into the chrome alt and it worked fine again, charging at 750 rpm. now it's doing the same thing again.Not charging at less than 1000 rpm.drops to 10v with heater and high beams on. So, why does it keep doing this,is there an armature issue? I tried a new reg today and it's the same. Help?
 
It's possible that you have an interaction (electrical interferance) from the msd.

It's also possible that you have a bad rotor. When rebuilders get ahold of these alternators, several things can happen

1 Rotors may be mixed into the wrong application. Please don't ask me what all the combinations are, don't know. I do know that some rotors are different. The round back rotors surely are different than square back, at the very least

2 Rotors (and even stators) can develop shorts such as a few shorted turns, and be difficult to run down. What this causes is for the rotor to develop less magnetism while drawing too much current. It also lowers efficiency, and causes heating, which might explain the diode failure.

Other than that, the only thing I can suggest is start over with a "known good" unit.
 
Under 12 volts when under 1000 r's ?
Was it making your battery go dead?




furyus2 said:
Hello,I need some help from the electrical guys on this site. I'm using this site instead of the B body forum because I know there are some really smart guys here. The car is a 64 Sport fury. It has a 440,and I converted it from the old style alternator and regulator to the square back alt and flat style reg. I have msd ignition,with no ballast resistor. There is no radio or electric fuel pumps or fans
What's happening is when I did the conversion it worked great. Then I came across a chrome alt that was supposed to be rebuilt and it worked great for a while,then it started to not charge (less than 12 volts) at under 1000 rpm. Above that it worked fine. So I took it to an alternator shop and he said the diodes were bad,and fixed them as well as press on a billet pulley from my March kit. Put it on and it worked ok for awhile then it would do the same thing,not charging at less than 1000 rpm. So I took apart the good (not chrome) alt. and put the stator and the diodes into the chrome alt and it worked fine again, charging at 750 rpm. now it's doing the same thing again.Not charging at less than 1000 rpm.drops to 10v with heater and high beams on. So, why does it keep doing this,is there an armature issue? I tried a new reg today and it's the same. Help?
Click to expand...
 
Sounds like chrome alternaters should be offered as empty housings to build a quality unit into. Good luck with it.
 
The battery is an optima. Cranks over great. I don't drive it long enough at the lower rpms for it to drain the battery. It usually only happens at a stop. What about going with a better setup like the one wire alts? is this a waste with my minimal electric requirements? And 67 dart, the msd was on when I had the single field and the other known good squareback alt. I guess I know I need to get another alt, but should it be another stock squareback or should I upgrade to something better. Not planning on any more electrical additions other than maybe an electric fuel pump one day. Whatever way I go, I have to have the billet pulley swapped. Is there a way to do this without a press? Thanks
 
furyus2 said:
The battery is an optima. Cranks over great. I don't drive it long enough at the lower rpms for it to drain the battery. It usually only happens at a stop. What about going with a better setup like the one wire alts? is this a waste with my minimal electric requirements? And 67 dart, the msd was on when I had the single field and the other known good squareback alt. I guess I know I need to get another alt, but should it be another stock squareback or should I upgrade to something better. Not planning on any more electrical additions other than maybe an electric fuel pump one day. Whatever way I go, I have to have the billet pulley swapped. Is there a way to do this without a press? Thanks
Click to expand...

If thats a under drive pulley it could be the root of your problem. If the alt turns slower at idle its internal fan also turns slower. It would still try to maintain the system voltage and eventually over heat.
 
RedFish said:
Sounds like chrome alternaters should be offered as empty housings to build a quality unit into. Good luck with it.
Click to expand...
I changed everything from my good alt except the rotor, and I guess my questions was can the rotor cause these symptoms? Can I get the billet pulley off without damaging it and can I do it without a press or junk all this and get a tuff stuff or powermaster alt or a one wire?:-k
 
You can pull the pulley the right puller, but you pretty much need a press to put it back on. I guess you could weld up a custom "c" clamp deal. Do NOT hammer it on.

There's lots of ways to go, but there's no reason why a good squareback and the Mopar regulator won't work just. Millions and millions of them were, and are, still on the road.
 
RedFish said:
If thats a under drive pulley it could be the root of your problem. If the alt turns slower at idle its internal fan also turns slower. It would still try to maintain the system voltage and eventually over heat.
Click to expand...
It did this before the pulleys were added, but I see your point,what can I do to keep it from doing this?
 
I would go to a GM Delco SI series alternator. Cheap, bulletproof, easy to fix, and charges extremely well. We're talking headlights, tailights, radio, blower fan on and still a rock solid 14V inside the car...on a $55 advance auto parts special with a lifetime warranty. Probably the best thing I ever did to the car outside of putting RMS strut rods on it.

Here's what I did on a small block http://www.forabodiesonly.com/mopar/showthread.php?t=154078
 
Well the new thing is I checked the voltage on the battery (an optima) and it read 2.6 volts. I unhooked the battery cables and the volts went to 4.6 WTF! Anybody know if this would cause the symptoms described? Right now it's on a charger.Help?
 
furyus2 said:
Well the new thing is I checked the voltage on the battery (an optima) and it read 2.6 volts. I unhooked the battery cables and the volts went to 4.6 WTF! Anybody know if this would cause the symptoms described? Right now it's on a charger.Help?
Click to expand...

do you mean 12.6 and 14.6?

are you unhooking the cables with the car running? if you are , its not a good idea because you can fry the diodes in the alternator. a normal "good" battery sits at 12.6 or so. i would re-ground everything including the engine ground/body ground and VR at the firewall first.

maybe 67dart273 will chime in and point you in the right direction
 
No, it's 2.6 with the cables on and 4.6 with them off engine off. Charged the battery at 40 amps for 85 minutes and the battery showed 12.79 volts, but if you watched the meter, it was losing volts as I watched From 12.79 to 12.78 to12.77 to 12.76. any ideas?
 
Offhand sounds like either the battery is toast, or discharged from a drain somewhere

Get the thing charged up and have it load tested

Then hook everything up except the ground, and hook a test light from the battery neg. post to ground. If it lights, with everything unhooked in the car, you have a drain somewhere.
 
O.K. 67 Dart,I will do those tests and thanks for the help. 73abodee I will read through that thread. I did have my alt checked at Advance auto, and it checked out alright. I already tired a new regulator so I'm charging the battery on a 10 amp for awhile then I will put the alt back on and check for a draw. Thanks again!
 
Take the battery to Autozone or Advance Auto. They will load test it for free. I have heard mixed things about those very expensive Optima gel batteries. Sounds like yours has an internal short.

If future charging problems, try applying full-field to the alternator. One terminal is always +12 V (w/ ignition switch on). Remove the other field connector and short the terminal to ground. That should make the alternator put out full current. If you still have an ammeter in the dash, you can read the current. Well maybe not, since the square-back can peg your ammeter (at higher rpm), which is another problem you should deal with. Either bypass the ammeter (run a thick wire from ALT output stud to BATT+) or search for my trick using diodes to shunt excess current to BATT+.
 
Well, I charged the battery and it seems to be holding a charge. Alt was checked out too. I put a multimeter on the alt and then the battery and found less than 1/10th of a voltage drop. also no draw on the system, but while checking things, I had the multimeter attached to the battery where I could see it from inside the car, and it was reading 1 volt higher than the autometer volt gauge on the dash. I hooked the multimeter to the same place the gauge was hooked and it read the same lower number.So the question is, Where is the best location for the positive wire from the volt gauge? Thanks
 
That's where it is now, but I'm getting a low reading. Could be a weak connection (bulkhead) I was thinking maybe the switched wire to the alt.
 
Am I going nuts or have some threads disappeared from this thread??
 
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