problems with charging circuit

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trudysduster

trudysduster

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something wrong with charging circuit. battery was dead the other day when trying to start the car. Duster 440. charged he battery back up. went down and bought a new alternator and voltage regulator. put it on and thought that was the end of the problem. took the car out for a drive today to make sure it was ok before we head to Indiana for a show Sat. pulled into the driveway coming home and the radio cut off for a short 4 seconds or so and then came back on. I wanted to make sure the alt. was charging so I pulled out the volt meter and checked the battery. 12.6 volts. started up the car and revved it up to about 2000 and the voltage never increased. stayed at 12.6. shut the car off and looked at things a minute and got back in the car and tried to start it and it just made one click. tried it about 10 times and it started. ran it a minute, turned it off and it would not hit. just a click. turned the ignition to run and shorted the starter relay and it just clicked. did that a few times and it finally started. shut the key off and tried it again and it just made one click. tapped the starter a few times and it finally started. now the question is : does the alternator charge the battery through the starter relay circuit. if the starter relay has been going bad, would that slowly run the battery down over the period of a week. I know that would cause the starter not to engage. would a bad starter relay allow the battery not to charge. I have ordered a new starter relay and starter in for tomorrow but would like to know if that is what the problem is here. I have had no problems with this car up until now. your ideas are appreciated. I would like to get this fixed before Sat. We are supposed to meet Kegan at the show on Sat. and I need this fixed. Thanks,Bill
 
I just checked the voltage coming out of the Batt. stud on the alternator. It reads 12.4 V also. even when the engine is revved. Is this normal. The battery cannot charge more than the alt. is putting out. what do you think here.
 
Multiple problems may be related. Anything from crappy battery terminals to failing ignition switch. See it don't take a lot of current to make a starter relay click. Much more is required to run the starter. Your repeated attempts could heat up a weak connection making it better, or worse. Then you need to properly power the alternator field and the regulator for those to operate properly.
Your one statement that leads me toward ignition switch is radio went off briefly.
From the ignition switch are several fairly large wires going to different places. One feeding a group of fuses, like radio. Another feeding ignition module, and so on.
Anyway... Some of the harness connectors that typically melt down, such as ignition switch connector under the column, engine harness connector under the hood ( certain year models), were molded in white plastics. I guess that was to make their burning easier to see. LOL
 
Hi Bill Hard to say, "guessing."

Try to narrow it down.

Take your test lamp or meter. There should be TWO quick connect field connectors, if the wiring is "original," you want blue, not green. The blue should have 12V ignition with the key in run.

Pull off the green field wire and ground that alternator field terminal.......the one you pulled the green off from. In dim light, with the key in "run" you should see a small spark

With that grounded, start and slowly bring up RPM while watching the voltmeter or ammeter. The ammeter should show a charge, the voltmeter should start to go up

If you have 12V on the blue, and the alternator won't charge with the other field terminal grounded, it most likely is bad alternator

If it DOES charge in this test, hook everything back up "normal."

2.......Make CERTAIN the regulator is GROUNDED. Pull off the regulator connector, and clip the green wire to ground in the regulator connector........the harness connector.

Repeat running the engine see if it charges.

If it does.............

Check the BLUE wire terminal in the VR connector. It also should have 12V with key in "run"

If so, and you are CERTAIN the VR is grounded, replace the VR

There has been a few guys "failing" these replacement VRs lately. This might be indicative of the current "Chineseo" trend.
 
I had a similar problem but with a few less conditions on my sons 78 Firebird. Battery just kept running down, new alternator, no joy. It ended up being the belt was too loose, it was glazed also. New belt and more tension and the alternator went from about 12.4 volts to 13.8, that's all it took. Good luck!
 
Del, I have 12 v on the blue. I saw a small spark on the green when grounded. It has like 1.5 V on it. I know the VR is grounded. I made real sure of that. I cant see how though that the voltage on the battery being at 12.6v without the car running would increase any at all if the alternator is only putting out 12.6 V at the Batt. terminal of the alternator. I was assuming the alternator should be cranking out 13.5- 14V and it didn't raise when I revved the engine. If I am only pushing 12.6 V off the Batt. terminal of the alternator, it is charging the battery the most it can, right. as far as the click when starting, I am thinking the starter may be bad. When I tapped on it a couple of times, it started. It seems like it may have a dead spot in it because it started fine just a little bit ago. This starter is under a lifetime warranty so I am going to replace it tomorrow. It seems like it may be dragging a little compared to Tylers starter which is new. But as far as the charging goes, if I am only getting 12.6 V out of the alternator, I cannot expect the battery to be charged more than that can I.
 
Ben, are you talking about the ignition lock assy. It wasn't too long ago we had the steering column apart for some reason and didn't notice any problems with the connectors. The battery terminals are new so I know that isn't the problem. I am going to get Tyler to pull the stereo back out and check the connections on it. He put that in and he isn't the best at making sure wires are covered. It just seems like a few things are happening at the same time and I am not sure they are connected but I will check all these out. especially the connections. Ratting around can cause wires and harnesses to loose connections.
 
trudysduster said:
Del, I have 12 v on the blue. I saw a small spark on the green when grounded. It has like 1.5 V on it. I know the VR is grounded. I made real sure of that. I cant see how though that the voltage on the battery being at 12.6v without the car running would increase any at all if the alternator is only putting out 12.6 V at the Batt. terminal of the alternator. I was assuming the alternator should be cranking out 13.5- 14V and it didn't raise when I revved the engine. If I am only pushing 12.6 V off the Batt. terminal of the alternator, it is charging the battery the most it can, right. as far as the click when starting, I am thinking the starter may be bad. When I tapped on it a couple of times, it started. It seems like it may have a dead spot in it because it started fine just a little bit ago. This starter is under a lifetime warranty so I am going to replace it tomorrow. It seems like it may be dragging a little compared to Tylers starter which is new. But as far as the charging goes, if I am only getting 12.6 V out of the alternator, I cannot expect the battery to be charged more than that can I.
Click to expand...

I neglected to mention........you are right..........12.6 is NOT charging. A fully charged battery "at rest" with the surface charge removed, IE sitting overnight SHOULD be 12.6 and "running" the charging system SHOULD be 13.8--14.2 as you said.

By grounding the field terminal as I mentioned, you eliminate almost everything except alternator

If it won't charge with that terminal grounded, and IF it's got 12V to the blue, and IF the battery output stud does not go "sky high" then it's right there in the alternator.

Still under warrantee?
 
Ok, I forgot to do that part. I will check that out and see what it is putting out. Thanks. I will let you know.
 
Del, I just checked this alternator again. engine off, key in the run position, I have 11.52 V on the blue field terminal. That is the lower terminal. I grounded the green terminal, the upper terminal on the alt. I started the car and had 12V. I ran the RPM's up and the voltage went up to about 18V on the meter. what does this tell you, regulator. Bill
 
Yup. Again, though make ABSOLUTELY certain it is grounded. Also, "wiggle" the crap out of the VR connector. They can go bad internally (wire broken) or get dirty / corroded.
 
I will take that back tomorrow instead of the alt. now, when I replace that and check the wires, how much should it be reading at the battery and how long will it take to read the right voltage there. I know it is grounded good. I scraped the paint off the regulator and under the regulator and where the bolts came through the inner fender I took it to metal so I know the regulator is grounded good. should I be getting the 13.5+ volts across the battery and will it take an hour or so to charge the battery to that voltage. I appreciate the help,Bill
 
Should not take long to see the voltage come up some. It should at least come up above 12.6 right away.
 
with everything hooked back up and a new VR, what should the voltage read from the Batt. terminal on the alternator if it is right. will it read the 13.5-14V as same as what should be across the battery when fully charged. How will I know the new regulator is good.
 
update on the Duster. I couldn't sleep good last night because my baby was not fixed yet. Woke up bout 3AM and went out to the garage and started on it. tore all the wires out to make sure it was wired right. When the parts house opened this morning, I returned the VR and exchanged it for a different brand. Pulled the starter and took it back in. It was under warranty. replaced the starter relay just for the hell of it. replaced the VR connector. made sure it was grounded real good. cut some pieces of wire out that didn't look real good to me and put it all back together. Started it up and took a reading at the battery. It read........................................14.38V. woo hoo. This puppy will be going to Indiana tomorrow morning. I want to thank all of you guys who helped me with this. especially Del. who PM,d me several times with info. I still have not address the issue with the radio cutting out for a minute yet but one step at a time. I may have my son pull the stereo out tonight and look at the connections.
 
Great.!!!! I "made the mistake" of agreeing to looking at a lawn tractor for a friend of mine, got nearly 3 hours into that PITA this morning. Got it running and usable, but you cannot make up for 15 years of neglect with a crescent hammer!!! LOL
 
another update on this problem. we went to a car show today over in Indiana and it took 1 1/2 hours each way to get there. I had the stereo on all the way over and back to see about the problem where it would cut out for about 4-5 seconds at a time. It would do this about every 5-10 minutes. Would you believe it didn't cut out not once all the way over and back. go figure. I don't know of anything I changed mentioned above that would have caused the problem. Don't you just love old cars.
 
If it was cutting out when you were having the "non charging" problem, there is some electronics that flat does not like low voltage. I would think a stereo of all things would be somewhat tolerant, as you often (or some people often) operate the thing with engine off
 
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