Electrical Help Please
- Thread starter SleeperDart505
- Start date
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SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
The battery wasn't dead. I was starting the car with it every time I went somewhere else. The Battery Tender goes into "float" mode when it gets the battery fully charged to prevent it from over charging. The light was solid green meaning it was fully charged when I left the house. I thought just driving 3 miles it would still be fully charged or close to it. I guess I'll take it out of the car and take it back down there for a load test after it gets back to fully charged again with the Battery Tender.
Yes. Actually there are several grounds all over this car. The guy who built it was making sure EVERYTHING was grounded. The alternator has it's own ground from the case to the fender, etc. all over the car.
First thing is to figure out if the ammeter is still connected as the factorry intended. IF it is, it will tell you more than a voltmeter.
The way car ammeters are set up is to indicate battery charging or discharging.
After the car starts, clearly the alternator is working (system voltage goes to 14+ V) On an electrical system that hasn't been altered the ammeter will then show battery charging. On your car, we need to figure out the wiring changes.
Please don't do that. It is unneccesary and can damage things.
None the less you have proven what many people have trouble beleiving, the car runs on the alternator.
I have no idea why did this.
1. A little low, but probably OK.
2. That's OK.
Where did you measure the voltage ?
3. Stop doing that!
We don't have enough information yet to make any decisions about alterations.
My suggestion would be to ditch the fans.
Good plan.
Another way to test the charge state of the battery is as follows:
Do a slow charge. 2 to 3 amps. If its a trickle - go overnight. If its an automaticly adjusting charger run it until it says fully charged.
Connect the voltmeter to the battery and unless you have really long leads, have a helper watch the meter while the engine is cranking. If it drops below 9.5 Volts the battery is weak.
SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
I was measuring the voltage on the battery posts. 12.5 not running. 14.25 or so running.
The amp meter in the dash appears to be working properly.
I'll try the 2 person check in the morning. The car is on a Battery Minder that has 4 stages of charging. The last stage is a float stage when the battery is fully charged.
Thanks!
Since you were measuring voltage at the battery, then with 14.2 V at the battery, the battery should charge and then maintain the charge.
If the battery proves to be OK, then if there is a low battery after driving around, it could be when the fans turn on, they draw too much power. Or depending on how they are wired in, the path from battery has less resistance than the path from the alternator.
If the battery proves to be OK, then if there is a low battery after driving around, it could be when the fans turn on, they draw too much power. Or depending on how they are wired in, the path from battery has less resistance than the path from the alternator.
A common technique for adding electrical equipment is to wire it in to the battery feed.
That can be OK for short time, high draw items, like a dump bed or a plow.
But if the engine is running, the ammeter will show power going though the charge line to the battery and then to the added equipment. So the ammeter is no longer reading just battery charging. Further, whenever the battery is running these items (alternator can't keep up or engine is off) the ammeter doesn't show the battery discharge.
I suspect this is one of the reasons ammeters disappeared from cars about the time TBI and electric fans became common.
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I would take the battery out of the car, charge it up, and take it in for a load test.
It sounds like your charging system is working reasonably well, based on the information you have provided. As said above, you may have too much electrical load for the alternator to keep up. Do not just switch in a higher amp alternator. Your wiring will likely need to be upgraded to handle the additional current. The bulkhead connectors and the amp gauge are weak spots.
On most Mopars I have driven the amp gauge usually barely moves during normal driving. If you are seeing big swings on the amp gauge, that is likely a sign that the system is not operating normally.
Pay attention to what Mattax says, he is the expert on thus kind of thing.
I have no idea what the wrench test means. We already know the current flowing through a coil of wire generates a magnetic field. All that tells you is some amount of current is flowing.
It sounds like your charging system is working reasonably well, based on the information you have provided. As said above, you may have too much electrical load for the alternator to keep up. Do not just switch in a higher amp alternator. Your wiring will likely need to be upgraded to handle the additional current. The bulkhead connectors and the amp gauge are weak spots.
On most Mopars I have driven the amp gauge usually barely moves during normal driving. If you are seeing big swings on the amp gauge, that is likely a sign that the system is not operating normally.
Pay attention to what Mattax says, he is the expert on thus kind of thing.
I have no idea what the wrench test means. We already know the current flowing through a coil of wire generates a magnetic field. All that tells you is some amount of current is flowing.
Inertia
Well-Known Member
There a lot of incompetent mechanics out there. Voltage readings can be deceptive. Charging system may be working ( 14.2v running), but I still question the condition of the battery to hold a charge. You must do a load test! If needed. take out your battery and take it to a qualified mechanic and let him charge it overnight and then load test it the next day. Then you will know.
Well this wrench test isn't something I'd recommend or even suggest.
But on the other hand it sure was a good demonstration what field means!
Inertia
Well-Known Member
Well this wrench test isn't something I'd recommend or even suggest.
But on the other hand it sure was a good demonstration what field means!
A quick easy test to figure out what's wrong, which bay and whose working on it.
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The only thing that the wrench test indicates is that there is current flowing in the field winding. This tells you nothing about the output side of the alternator, since there is no transformer action when it is not spinning.
Not trying to be combative, just think it tells very little about the health of the charging system.
Inertia
Well-Known Member
With no magnetism, it indicates the field circuit is faulty. Could be reg.
If it had magnetism, then the reg is working, and the issue is at the alternator
The test was never meant to test output, but to quickly determine which item to buy on the way home, after you had to get a jump start at the supermarket, - as I mentioned in the original post. lol
Or for me to diagnose at reception, which bay it's going in, and who is to work on it
Not always, but experience has proved it reliable.
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Maybe posting little further explaination would be useful.
Volts are a measure electrons excited. More represents higher energy in action or potential.
Amps are electrons moving.
The voltage measurements, even at the battery, do not reveal if the battery is charging.
They only show the potential to charge.
If the battery is already fully charged, there will be no more chemical reaction, and no current.
Similarly if the acid was worn out or cooked out.
A good example of this was when the battery negative was disconnected with the engine running. The voltage at battery positive was still 14.2, but electrons could not flow because the circuit was open. This lack of flow could be seen on an ammeter but not on a voltmeter.
Volts are a measure electrons excited. More represents higher energy in action or potential.
Amps are electrons moving.
The voltage measurements, even at the battery, do not reveal if the battery is charging.
They only show the potential to charge.
If the battery is already fully charged, there will be no more chemical reaction, and no current.
Similarly if the acid was worn out or cooked out.
A good example of this was when the battery negative was disconnected with the engine running. The voltage at battery positive was still 14.2, but electrons could not flow because the circuit was open. This lack of flow could be seen on an ammeter but not on a voltmeter.
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I never want to just toss new parts at a problem, but I admit I want a battery that is NOT 4 years old IF trying to diagnose mechanical problems. More than likely about time for a new one.
I want a known good carb.'
I want a known good distributor.
MSD ignition and solid core wires maybe an issue???????
I want a known good carb.'
I want a known good distributor.
MSD ignition and solid core wires maybe an issue???????
Inertia
Well-Known Member
The average life of a lead-acid battery is 5 - 7 years.
If buying a new battery, always chose a battery with equal electrolyte levels. (White case)
Uneven levels already has the battery on its way out .
If buying a new battery, always chose a battery with equal electrolyte levels. (White case)
Uneven levels already has the battery on its way out .
SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
More Confused Than Ever..............
I removed the battery and alternator today. I took them to Advance Auto Parts and Auto Zone both to see what they both had to say about them when they load tested them out of the car.
Advance Auto says battery is OK. They said the Alternator is bad after load testing both. Advance Auto could not get an alternator like I have. I'm not sure because I didn't buy it but it looks like the one on a 1972 D300 pickup. "Square back alternator" I think it's called. 60 amps. Nothing special. Since I couldn't buy it there I went across the street.
Auto Zone says battery is OK. I did see the battery was showing 58% after being load tested twice. Seemed kinda low to me for a good battery? I came home and put it back on the Battery Tender and it confirmed it was below 75% charge by the LED lights that were lit. However, the flashing green LED that came on 5 minutes later told me the battery was up to 80% charged again. Auto Zone said Alternator is OK. Advance said alternator was bad. Who do I believe?
Suggestions????
I removed the battery and alternator today. I took them to Advance Auto Parts and Auto Zone both to see what they both had to say about them when they load tested them out of the car.
Advance Auto says battery is OK. They said the Alternator is bad after load testing both. Advance Auto could not get an alternator like I have. I'm not sure because I didn't buy it but it looks like the one on a 1972 D300 pickup. "Square back alternator" I think it's called. 60 amps. Nothing special. Since I couldn't buy it there I went across the street.
Auto Zone says battery is OK. I did see the battery was showing 58% after being load tested twice. Seemed kinda low to me for a good battery? I came home and put it back on the Battery Tender and it confirmed it was below 75% charge by the LED lights that were lit. However, the flashing green LED that came on 5 minutes later told me the battery was up to 80% charged again. Auto Zone said Alternator is OK. Advance said alternator was bad. Who do I believe?
Suggestions????
Get them tested again and go for best two out three? Haha.
Many of the auto parts stores are populated by nitwits anymore. Is there a NAPA by you? They seem to have a better class of help. Or is there a local garage that will check it for you? Might be worth a few bucks to get it done properly.
Maybe I missed it earlier, but how old is the battery?
Many of the auto parts stores are populated by nitwits anymore. Is there a NAPA by you? They seem to have a better class of help. Or is there a local garage that will check it for you? Might be worth a few bucks to get it done properly.
Maybe I missed it earlier, but how old is the battery?
SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
Battery is dated 1/2020 so it looks like it's 4 years old.
At this point I'm thinking about buying an alternator and a battery both. The alternator is questionable and the battery will take a charge but it sure discharges quickly with the slightest usage. Thoughts?
Where does the voltage regulator come in? Could this be the issue with the alternator giving conflicting readings? (one store says bad the other store says good?) The Parts Store guys weren't sure..........
At this point I'm thinking about buying an alternator and a battery both. The alternator is questionable and the battery will take a charge but it sure discharges quickly with the slightest usage. Thoughts?
Where does the voltage regulator come in? Could this be the issue with the alternator giving conflicting readings? (one store says bad the other store says good?) The Parts Store guys weren't sure..........
Now co'mon.
You've already demonstrate to yourself in two ways that the alternator works.
Don't beleive your own eyes, and in your case, your hand?
The regulator.
When the engine was running and you were measuring voltage at the battery, it was 14.2 volts. That certainly suggests it too was working.
You've already demonstrate to yourself in two ways that the alternator works.
Don't beleive your own eyes, and in your case, your hand?
The regulator.
When the engine was running and you were measuring voltage at the battery, it was 14.2 volts. That certainly suggests it too was working.
SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
I don't think these wires are solid care. Maybe you or someone could confirm they are OK to use with DSD 6???
SleeperDart505
Stock wheels, Stock Paint, 505" Stroker, Full Cage
OK so you're saying that the alternator and voltage regulator should both be good? And am I to infer since you didn't mention the battery that you think it is the issue?Now co'mon.
You've already demonstrate to yourself in two ways that the alternator works.
Don't beleive your own eyes, and in your case, your hand?
The regulator.
When the engine was running and you were measuring voltage at the battery, it was 14.2 volts. That certainly suggests it too was working.
Without seeing how the two places tested, and the test equipment settings, must say its probably best to write off both tests.
Although it sounds like you were able to observe the one battery test. Maybe you can fill in more info.
Basically the battery test is create a load similar to a starter and measure current and voltage. However instead of comparing with the starter current, the comparison is based on the energy the battery is supposed to have stored when fully charged (3 times the AH rating or 1/2 the CCA).
Here's a battery test procedure using a Sun VAT-40. Its relatively modern so an inductive pickup clamp to measure current.
As far as the regulator goes, you can observe if the voltage stays consistant with increasing rpm.
You can measure at the battery. If that's good, go around and measure the at the alternator output - carefully!! Don't short the output terminal connection with the test lead.
Although it sounds like you were able to observe the one battery test. Maybe you can fill in more info.
Basically the battery test is create a load similar to a starter and measure current and voltage. However instead of comparing with the starter current, the comparison is based on the energy the battery is supposed to have stored when fully charged (3 times the AH rating or 1/2 the CCA).
Here's a battery test procedure using a Sun VAT-40. Its relatively modern so an inductive pickup clamp to measure current.
As far as the regulator goes, you can observe if the voltage stays consistant with increasing rpm.
You can measure at the battery. If that's good, go around and measure the at the alternator output - carefully!! Don't short the output terminal connection with the test lead.
I wouldn’t rely on a 4 year old battery.
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