Alternator/charging questions

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A 1 V drop is a lot. If near the full ~70A alternator output, that is 70 W of heat being dissipated somewhere. Main suspects are the bulkhead connector, ignition switch, or fuse box, if on the high side, or maybe a bad engine to frame ground or BATT- to engine ground. Most connectors and switches would melt after a long time of 70 W heat.

Once you locate the main drop, there are various solutions. The bulkhead terminals can be removed and sanded, then re-assembled with dielectric grease. Ditto for fusebox and grounds. New ign switches are ~$12 for many (my 64 & 65 A's). I have my ign switch turn on a 30A relay to provide ACC power, so the switch only conducts ~50 mA.
 
Our car was always dead or close to it. Had / has a chrome alternator (Tuff Stuff one wire) and new optima. We thought the battery was problematic or the alternator was fickel.
So, we found out that optima batteries take forever to charge and you cannot expect them to charge properly using high amp rate.
That is my experience with optima (yellow). Talked to them specifically about it at length. Charge at 3-5 amps for 24 - 30 hours.

After the 2 day charge based on recommendations from optima, our chrome alternator and battery behave normally, friggin a bit of dim lights at idle like all older mopar but at speed above 1100 rpm it is great.
Stop and go driving may not recharge the optima because charging at 50 amps or more from the alternator for 30 minutes will show good voltage and the battery will just die back down as it has not been saturated. We usually drive the car for 30 minutes to 2 hours at a pop and put it on the trickle charger occasionally. Output of our alternator around 2k is easily 14.6 - 15 after start and tapers down to like 14, so alternator is good I figure. Just sharing our experience.
Try trickle charging for a couple days if you can so your battery is saturated really well. Then start from there.
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If this is true, good reason to "not" run these batteries.

I've always been "old school" on batteries. Buy them locally, and buy them by WEIGHT. Manufacturers can put any kind of promise on the label, but the WEIGHT is what makes the thing work!!
 
Well I did find a ground that wasn't soldered right. Repaired that and cleaned all the usual grounds(battery, block, vr .Seems to charge better but I still need to go through the list that 67 dart linked me to. Also, ever since I've had this car, at idle when I hit the brakes, I see a 1/2 volt drop on the gauge. I put an ohm meter on the taillight sockets and got 0.00 so I am wondering if it's possible the switch is pulling too much power and how to check? Thanks
 
Also wanted to add that I checked the voltage drop and got .34 I checked it from the battery to the 12v switched wire at the alt. Was this correct? I have no ballast resistor (msd) and the head lights seem to pull alot of current.The gauge drops about 1 1/2 v when I turn on the lights. 1/2 more if I use high beams. Is this too much? should I use relays ? Connected the meter to the batt neg to the vr body set to volts. Got 0.00 switched to ohms and got 0.00 with the engine running.
 
.34 is not all that bad. The way this works is, that line is the switched "ignition run"

So you are measuring the drop all the way from the battery, through the firewall, ammeter, igntition switch, back out through the firewall, and in this case to your alternator field.

THE DROP (in this case .34) is what the regulator "I" terminal "sees" and so it adds this to it's own set point. That means that if the regulator is at 14, it adds .34, for 14.34. So you can see that yours ain't bad.

I would find another battery (even borrowed) that you can test with that you know is good.

I can't figure out yet why your voltage takeoff point for your voltmeter is low. You surely have a drop somewhere Where do you have it hooked? accessory? Ignition run?

Surely you don't have it "on" all the time?

Also, you might check for a parasitic drain. Make sure everything is off including trunk light, etc, and hook a test lamp in series with the battery ground. If you get no light, put your multimeter in series instead of the lamp, starting with the highest amperage / milliamp setting on the meter, and see if you have a drain.

One "popular" cause is leaky alternator diodes. This of course is easy to verify -- if you show a drain simply unhook the alternator charging line and see if it goes away
 
67Dart273 said:
.34 is not all that bad. The way this works is, that line is the switched "ignition run"

So you are measuring the drop all the way from the battery, through the firewall, ammeter, igntition switch, back out through the firewall, and in this case to your alternator field.

THE DROP (in this case .34) is what the regulator "I" terminal "sees" and so it adds this to it's own set point. That means that if the regulator is at 14, it adds .34, for 14.34. So you can see that yours ain't bad.

I would find another battery (even borrowed) that you can test with that you know is good.

I can't figure out yet why your voltage takeoff point for your voltmeter is low. You surely have a drop somewhere Where do you have it hooked? accessory? Ignition run?

Surely you don't have it "on" all the time?

Also, you might check for a parasitic drain. Make sure everything is off including trunk light, etc, and hook a test lamp in series with the battery ground. If you get no light, put your multimeter in series instead of the lamp, starting with the highest amperage / milliamp setting on the meter, and see if you have a drain.

One "popular" cause is leaky alternator diodes. This of course is easy to verify -- if you show a drain simply unhook the alternator charging line and see if it goes away
Click to expand...
The battery holds 12.6v. Is that good? The volt gauge (no ammeter) is hooked to a switched accessory. May need cleaning. Where is the best location for it? Car seems back to normal after fixing the ground which means the car charges between 13.5 and 14.5 at cruise rpm. I still have the low readings only with the headlights (high beams) heater/blower on it barely reads 12v at the battery idling in gear at 800 rpm. would light relays help? Brake light causes dash lights to flicker once on application Is this normal? switch bad? Thanks for all your help so far.........:prayer:
 
furyus2 said:
The battery holds 12.6v. Is that good? The volt gauge (no ammeter) is hooked to a switched accessory. May need cleaning. Where is the best location for it? Car seems back to normal after fixing the ground which means the car charges between 13.5 and 14.5 at cruise rpm. I still have the low readings only with the headlights (high beams) heater/blower on it barely reads 12v at the battery idling in gear at 800 rpm. would light relays help? Brake light causes dash lights to flicker once on application Is this normal? switch bad? Thanks for all your help so far.........:prayer:
Click to expand...

12.6 is perfect

mine runs at 13.8 - 14 cruising

at idle im at about 12.2 or so.

check your rear light harness for a good ground, they need it.

you are getting there for sure.

i mounted my volt gauge on the bottom of the dash where i can see it.
 
That low reading with lights on is troubling

Have you verified that the alternator actually can put out decent amperage, and has no bad diodes?

You have any idea what the amperage rating is supposed to be on the alternator?

I understand you bypassed the ammeter, right?

What happens to the lights on/ voltage if you ground the green regulator field connection? (This should "full field" the alternator. be carefu the voltage does not go too high

Almost sounds like you have an alternator problem, now.
 
That low reading with lights on is troubling

Have you verified that the alternator actually can put out decent amperage, and has no bad diodes?

I took it to autozone, and they said it was good. didn't tell what it was putting out at what rpm.

You have any idea what the amperage rating is supposed to be on the alternator?

no,supposed to be a stock 1972 squareback, whatever they are rated at.

I understand you bypassed the ammeter, right?

yes I have both the red and black wires connected to the black side of the ammeter.

What happens to the lights on/ voltage if you ground the green regulator field connection? (This should "full field" the alternator. be carefu the voltage does not go too high
I will have to check that. should this be checked in gear at idle since this is where my problem lies?

Almost sounds like you have an alternator problem, now.

If it is the alternator, what's your opinion on a powermaster alt? I'd like to keep it all mopar and I've already invested in a march billet pulley and would like to use it. Thanks Dave
 
There's no reason why a properly operating squarback wont' work fine. They came on millions of Mopar vehicles. The thing I don't like about powrmaster and other similar, is they don't use factory parts
 
73AbodEE said:
12.6 is perfect

mine runs at 13.8 - 14 cruising

at idle im at about 12.2 or so.

check your rear light harness for a good ground, they need it.

you are getting there for sure.

i mounted my volt gauge on the bottom of the dash where i can see it.
Click to expand...
Ok, but i keep asking, where is the best place to wire the volt meter to. Should it be connected to the wire that feeds the alt? where else? Thanks
 
furyus2 said:
Ok, but i keep asking, where is the best place to wire the volt meter to. Should it be connected to the wire that feeds the alt? where else? Thanks
Click to expand...

i have my new volt meter wired from a switched hot out of the fusebox and grounded to the dash frame. take your tester and find a fuse that only gets power when the key is on and run the hot straight off if it.
 
I checked the taillight sockets with an ohm meter and got 0.00.So they are grounding well. What about the brakelight switch? when I apply brakes I see a large flicker and a 1/2 v drop. Is this normal?
 
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