Doesn't seem to be charging properly

[MaximRecoil]

The double blue connection wires usually is blue with white tracer and a dark blue.

Yes; they look black in my car, but I can see that they were probably once dark blue.

Hopefully you got it straightened out and working

Well it seems that I've had the wiring correct all along, but I'm still only showing 12.5 - 12.7 volts at the battery, and about 12.5 at the alternator. Those voltage readings were relatively steady after I bypassed the car's alternator gauge (prior to doing that, the voltage fluctuated rapidly between mid 12s and low 13s).

Also, the battery that is in there now is not so great (it won't hold a charge for very long). Could that be the problem?

[nascarxx29]

A good battery will help

[tan top]

the blue or  green field conections  on the back of tha alternator !  does  not   matter which way round they go    , but i always put them like diagram !

but yes in answer to your question , you need to swap the conections around to the way i have altered your picture !

Your altered pictures are not like the diagram; they are opposite of the diagram. Both diagrams I have posted show the center blue wire of the plug going to the positive field terminal on the alternator; which is how I have it wired on my car. Your altered pictures show the center blue wire of the plug going to the negative field terminal on the alternator.

make sure all the splices are good , crimping is not really ideal , need to solder the splices really  

Solder is far from ideal for wiring in a car environment. Solder does not flex particularly well, and given enough vibrations, it can crack/break. Crimping on the other hand, is ideal, which is why the factory that built the car crimped all the connections in the first place, rather than soldering them. Look at the bulkhead connectors sometime; there are nearly 50 factory crimps just there alone, to say nothing of the rest of the harnesses.

A proper crimp is stronger than the wire itself; meaning, you can not pull the crimped connector off without breaking the wire. A proper crimp is also airtight, which prevents corrosion. Plus, crimps are far more suitable for flexing than solder is. Solder is ideal for plumbing, attaching components to PCBs, and other applications not subject to much movement like wiring (especially in a vehicle) is.

In any event, I bypassed the alternator gauge today by attaching both wires to the same post on the back, and that got rid of the rapid fluctuations in the voltage readings, but it is only showing about 12.5 - 12.7 volts at the battery when the engine is idling. It is also only showing about 12.5 volts at the alternator. And just for the heck of it, I did try it with the 2 field wires at the alternator switched around, with no change in results.

Is this a system that only charges when it needs to, i.e., when there is a draw on the system (such as headlights)? I don't have my headlights wired up yet, so I haven't been able to test the voltage with the headlights on.

 

sounds like you got it fixed ?  & no  need for my help after all , thanks ! i think ,for letting me try & help you though! !  

good you got it sorted   

[MaximRecoil]

 

sounds like you got it fixed ?  & no  need for my help after all , thanks ! i think ,for letting me try & help you though! !  

good you got it sorted   

Fixed? No. I haven't changed anything since I started this thread other than bypassing the alternator gauge. As far as I know I should be getting a relatively steady voltage reading in the high 13s to low 14s at the battery while the engine is running, but I'm only getting mid-to-high 12s.

Here's some questions from this thread that I'm still wondering about:

1. I've heard that the car's alternator gauge is a critical part of the charging circuit, so if something is screwy with that, it won't charge properly. I was thinking about adding a jumper wire across the two terminals of the gauge to eliminate that potential problem (any thoughts on this?).

2. Are there any other parts of the charging circuit I should test?

3. Is this a system that only charges when it needs to, i.e., when there is a draw on the system (such as headlights)?

[b5blue]

A nothing less that excellent battery is mandatory for these old factory systems to have any hope. (Due to weak idle output.)

[nascarxx29]

You need to have a good battery stationary voltage should read 12 or 12.5 volts.With out the car running.Running should be 13.5 or then some.Mopars discharge at low speed to due pulley speed inherit problem.And there many modifications to improve on the mopar charging system. From GM or Powermaster 1 wire alternator or a Nippo Denso Japanese unit

http://www.dodgecharger.com/forum/index.php/topic,64454.msg721348/topicseen.html#msg721348

[tan top]

A nothing less that excellent battery is mandatory for these old factory systems to have any hope. (Due to weak idle output.)

You need to have a good battery stationary voltage should read 12 or 12.5 volts.With out the car running.Running should be 13.5 or then some.Mopars discharge at low speed to due pulley speed inherit problem.And there many modifications to improve on the mopar charging system. From GM or Powermaster 1 wire alternator or a Nippo Denso Japanese unit

http://www.dodgecharger.com/forum/index.php/topic,64454.msg721348/topicseen.html#msg721348

1 -- as far as i know  the amp gauge only really gives problems when the connections become loose & or the insulation brakes down & causes a short ?? then big problems !
http://www.madelectrical.com/electrical-tech.shtml
i would bolt them togeather & insulate !  completely by pass the amp gauge ,  infact thats what i have done my self ,( & converted factory amp to a volt gauge ) but my own take on the mad amp meter by pass , & more or less  completely redesigned the whole charging circuit / power supply  , ( got a bit carried away really adding blade fuses & stuff to protect circuts , & prolly no need of that many , but while i was redoing  stuff , might as well put them in , just my preference ) but still using the  factory duel filed alternator !

using a jumper wire between the two terminals on the rear of the amp gauge ,  would work , but would be worried about more stuff being bolted & the already inadequate terminal insulation through the grounded metal gauge cluster body !   !!

like was mentioned the mopar idle charging , at least with the oem alternators  is not good !!  , to make sure its charging  properly  i would increase the revs to 1200ish rpm while checking  just to eliminate low  oem mopar charging at  idle .

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2 -- would check the  firewall block connector  , the middle one carries the battery / alternator charging power , make sure they are free from corrosion etc , big mopar problem especially on cars that have been sitting for any length of time , would be a good idea to check the lot while your at it , & any broken or frayed wires ! check & clean starter relay conections too

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3

yes  sort of ,   battery volts should be at least 12.5 -12.8ish + - , when engine not running
with motor idling with no electrical load about 13.5  - 14.8 + - even as high as 15 , but anything over you have a problem , when using   high load electrical stuff, headlights , blower fan motor !  etc etc if you wire up a volt meter when the motor is running you will see a momentary drop in voltage , but then if every thing working ok , it will return to about  idling with no electrical load 13.5 .14.8 ,
although like i mentioned , mopar charging at idle is not the best , so would increase revs to what i have previously mentioned , to check!

lastly , if your charging system is working correctaly , & your battery is partialy discharged ! when you start the motor , the amp & or volt meter will prolly read as high as 15.5 volts  or 20ish + amps while the alternator is charging the battery up  ,  the gauge should return to just to the plus side on the amp gauge & 13.5 -14.8 on a volt gauge/meter after a short while , minute or two

below
another picture how the 70 & up electronic voltage regulator should be hooked up

[elacruze]

Test for AC voltage across the alternator stud and case, maybe you lost one of the diodes. If you lose a diode you lose 1/3 of the capacity, and either lose the circuit completely or it goes AC and becomes neutral to the charging process. You can test the diodes individually but you may have to take the case apart. You should be able to find an auto parts with a proper alternator test stand somewhere nearby.

[MaximRecoil]

Test for AC voltage across the alternator stud and case, maybe you lost one of the diodes. If you lose a diode you lose 1/3 of the capacity, and either lose the circuit completely or it goes AC and becomes neutral to the charging process. You can test the diodes individually but you may have to take the case apart. You should be able to find an auto parts with a proper alternator test stand somewhere nearby.

How much AC voltage would be correct?

So does the case of the alternator need to be grounded? I'm sure it is already grounded because it is installed using clean factory brackets, but if the ground of the alternator case is critical, I could add a dedicated ground wire to it to be sure.

[elacruze]

Test for AC voltage across the alternator stud and case, maybe you lost one of the diodes. If you lose a diode you lose 1/3 of the capacity, and either lose the circuit completely or it goes AC and becomes neutral to the charging process. You can test the diodes individually but you may have to take the case apart. You should be able to find an auto parts with a proper alternator test stand somewhere nearby.

How much AC voltage would be correct?

So does the case of the alternator need to be grounded? I'm sure it is already grounded because it is installed using clean factory brackets, but if the ground of the alternator case is critical, I could add a dedicated ground wire to it to be sure.

Theoretically, there should be Zero AC voltage. Typically in my system I find .3-.5 volts AC. I have a dual-field squareback 78 amp unit from a '96 Durango, but there is little difference all the way back to '74 or so. Even the older single-field alts should have no AC voltage.

Case ground is critical on single field alts since the circuit is completed through the case, but not so important on dual field since the regulator controls the ground circuit through the fields. I always insure a secure ground in any case, just to be certain nothing can be ground looped. (ground loop is a difference in electrical potential at different grounding points)

[MaximRecoil]

Okay, so if I get significant AC voltage across the alternator stud and case, that means I've got a bad diode and the alternator is doing nothing to charge the battery?

I believe the system is charging somewhat. I show ~12.5 VDC across the alternator stud and ground, and the battery shows a relatively steady 12.5 - 12.7 VDC while idling (revving the engine doesn't change the voltage). The reason I believe the system is charging somewhat is because before I did the electronic regulator conversion, I know for a fact it wasn't charging, and the battery voltage would be at around 12.5 VDC before starting, but would drop to around 10.5 volts within a minute or two of idling. But the way it is now, it just stays at 12.5 - 12.7 VDC even if I let it idle for 20 minutes. If it wasn't charging at all, the battery voltage would drop quite low after 20 minutes of idling, rather than stay the same.

The first thing I'm going to try is to swap in a different regulator and/or alternator to see what effect that has (there are lots of Mopar regulators and alternators in the junkyard behind the place where I'm working on the car).

[MaximRecoil]

I switched the alternator with another one this morning, and no change. Then I was about to look for another regulator to try when my mechanic friend walked over. He unplugged the regulator as the car was idling and wanted me to check the voltage. It dropped to 9 someodd volts when he did that (bad battery and all), down from about 12.5 VDC when the regulator was plugged in. Then he jumped something on the regulator and/or plug with a screwdriver, and wanted to know what the voltage was now. It jumped to 16 or 17 VDC at the battery when he did that. He said, "It's the regulator. Grab one off that Dodge van over there." He was right. When I hooked up the other regulator, I got 14 VDC at low idle at the battery, and 14.4 VDC at high idle.

[b5blue]

 

[tan top]

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