Electrical Help Please

[SleeperDart505]

I'm no good with electronics so I need some help with my '68 Dart with a 505"/440 stuffed into the engine bay with the battery moved to the trunk. First time I drove it I stopped to put gas in the car. Then I went to show the car to my father-in-law. Then I stopped at Wendy's on the way home. The battery died at Wendy's and I had to call my wife to jump me off.

The car is slow to start like the timing is too high or like it has a lot of compression. It eventually kills the battery. I'm afraid to drive the car because I don't want to get stranded. I have hooked a Battery Tender to the battery so it will give a slow trickle charge and the battery will be fresh every time I drive it. I also moved the timing temporarily so it's easier to crank. It still seems to run good but it's been 20 degrees outside so I haven't really done much to it yet like actually checking the timing with a timing light.

I called the previous owner and he said the same thing had been happening to him. He suggested a voltage regulator. Would a bad voltage regulator cause the battery not to hold a charge? I think that's a stock type MOPAR voltage regulator on the firewall in the pic. Seems like the alternator might be bad? How can I tell. Someone mentioned to remove the positive battery cable from the battery while it was running? What would that show?

Thanks for the help in advance.

 

[Murray]

#1- check the condition of the battery with a load tester. If the battery is good, then #2- check the charging system. If it's working, then #3- really set the timing with a timing light, no guessing. Tell us what you find.

 

[Super-Cuda]

#1- check the condition of the battery with a load tester. If the battery is good, then #2- check the charging system. If it's working, then #3- really set the timing with a timing light, no guessing. Tell us what you find.

I would add weak starting motor to that list as well.

 

[Professor Fate]

Multiple short trips don't give the battery sufficient time to recharge fully between starts, either.
As said, time to start diagnosing the battery and charging/starting systems.
Stock starter?

 

[tonysrt]

Do you have a voltmeter in the car? If not put a voltmeter on battery with car running to check output of alternator should be at least 13 volts or more when at fast idle, about 1000 RPM. If you don't have a voltmeter, get one to do any electrical troubleshooting. Harbor Freight has one for about $5. Maybe even an Auto store as Advance auto or auto zone can check charging system for you.

 

[65TerrorCuda]

Get one of these and see what's going on as you drive. Goes into a cigarette lighter. Can also see how miserable you are when it's 99 degrees in the car. Thank you headers

 

[Inertia]

Turn key on, don't start.
Take ferous metal object (screwdriver/wrench), place in front of alternator pulley if shroud will allow, or back of alt, but don't touch any wires.
If you have a strong magnetic pull the object to the alternator, that indicates the brushes, rotor, voltage reg., and wiring are working.
This usually indicates the rectifier (diodes etc) aren't working.
If no magnetic pull, the voltage regulator, brushes, wiring would be suspect.
This is an out in the field test to get an idea what to buy on the way home .
Proper diagnostics with guages is preferable .

 

[jos51700]

 

[Mike69cuda]

Here what I would do:

1. Check the battery voltage while the car is off. It should read about 12-12.5 volts.

2. Start the car. Check battery voltage. It should go up about 2 volts. Should be about 13.5 to 14.5 volts. If it doesn't go up it is not charging. Could be a number of things including alternator or regulator.

3. Start the car and take the negative battery cable off. If the car dies, the alternator is not charging. If it stays running you alternator / voltage are likely ok.

4. Take the alternator off and have it checked at auto parts store. If it tests good, buy a regulator and see if that fixes it.

if your car cranks good when you jump it, the starter is probably ok.

 

[Kendog 170]

I have the same type issue. Check your grounds and the way the trunk mount battery is wired. That was my issue, I think. I'm still doing other things and am waiting for warm weather.
I think if you disconnect negative while running, it should stay running? If it dies, some type of charging issue? IDK but someone will correct me.
67Dart273 will chime in. He knows his stuff.

 

[SleeperDart505]

Do you have a voltmeter in the car? If not put a voltmeter on battery with car running to check output of alternator should be at least 13 volts or more when at fast idle, about 1000 RPM. If you don't have a voltmeter, get one to do any electrical troubleshooting. Harbor Freight has one for about $5. Maybe even an Auto store as Advance auto or auto zone can check charging system for you.

I have the stock AMP meter in the car. It is moving from straight up to far right at times and middle right while I drive. The electric fan came on at Auto Zone. Stayed on for a few minutes with the car not running while I was there. When I restarted the car it was slow to start..... but it started. Then the AMP meter in the dash swung all the way to the right like it was charging............

 

[Mike69cuda]

If you have a big electric fan and have not upgraded your charging system, that could be an issue.

 

[SleeperDart505]

I have the same type issue. Check your grounds and the way the trunk mount battery is wired. That was my issue, I think. I'm still doing other things and am waiting for warm weather.
I think if you disconnect negative while running, it should stay running? If it dies, some type of charging issue? IDK but someone will correct me.
67Dart273 will chime in. He knows his stuff.

I disconnected the negative battery cable from the battery and let it idle about 5 min. It stayed running the whole time.

Could it be the alternator is not putting out enough amps for the car? It has a couple electric fans, MSD 6 ignition, A long battery cable to the trunk...........I'm sure that pulls a heavier load when cranking the engine, and the big engine with possibly higher compression? Would a stock 60 amp alternator handle all this? Or should I be looking at a 95 amp alternator???

#1- check the condition of the battery with a load tester. If the battery is good, then #2- check the charging system. If it's working, then #3- really set the timing with a timing light, no guessing. Tell us what you find.

#1- check the condition of the battery with a load tester. If the battery is good, then #2- check the charging system. If it's working, then #3- really set the timing with a timing light, no guessing. Tell us what you find.

Took the car to Auto Zone. Nobody had ever seen a battery in a trunk before. They dutifully hooked up their hand held computer load tester thingy and it said my battery had 0% charge. I said so it shouldn't start then if it's completely dead. Right? She agreed. So I started the car for her. She called the Manager. He was just as useless as his employee.

So I left and went across the street to Auto Zone. This guy liked the old car but really couldn't be of much help either. His hand held load tester thingy said the battery had 575 amps. He THOUGHT my battery should have 800 but wasn't sure. He couldn't tell from the part number and it's not spelled out plainly on the sticker on the battery like it's supposed to be. So he assumed the battery was low. The electric fan had kicked on and run for a few minutes and I had driven across the street so maybe that's why the battery was low? So this guy couldn't swear ot was the battery or the alternator or the voltage regulator. I should have stayed home and studied the inter-web some more.......

 

[SleeperDart505]

Turn key on, don't start.
Take ferous metal object (screwdriver/wrench), place in front of alternator pulley if shroud will allow, or back of alt, but don't touch any wires.
If you have a strong magnetic pull the object to the alternator, that indicates the brushes, rotor, voltage reg., and wiring are working.
This usually indicates the rectifier (diodes etc) aren't working.
If no magnetic pull, the voltage regulator, brushes, wiring would be suspect.
This is an out in the field test to get an idea what to buy on the way home .
Proper diagnostics with guages is preferable .

I turned the key on and held a wrench in front of the alternator pully. It almost jerked it out of my hand. Does that mean the alternator and voltage regulator are probably OK?

"This probably means The rectifier and diodes aren't working". Are they supposed to with the key on and the car not started? (I had an electrical by-pass as a child)

 

[Inertia]

I turned the key on and held a wrench in front of the alternator pully. It almost jerked it out of my hand. Does that mean the alternator and voltage regulator are probably OK?

"This probably means The rectifier and diodes aren't working". Are they supposed to with the key on and the car not started? (I had an electrical by-pass as a child)

Good conclusion.
I wouldn't be buying a regulator on the way home, I agree it's likely the rectifier, if it's not charging, or something inside the alt,. "output" side.
A voltage reading would be nice.
Running should be 13.8 - 14.2 ish .
(The rotor/pulley needs to be turning to sense/test the pulses from the diodes).
Cheers

 

[SleeperDart505]

Here what I would do:

1. Check the battery voltage while the car is off. It should read about 12-12.5 volts.

2. Start the car. Check battery voltage. It should go up about 2 volts. Should be about 13.5 to 14.5 volts. If it doesn't go up it is not charging. Could be a number of things including alternator or regulator.

3. Start the car and take the negative battery cable off. If the car dies, the alternator is not charging. If it stays running you alternator / voltage are likely ok.

4. Take the alternator off and have it checked at auto parts store. If it tests good, buy a regulator and see if that fixes it.

if your car cranks good when you jump it, the starter is probably ok.

OK Mike, Here's what I did............
1. I checked the voltage with a meter at the battery with the car off. It was about 12.5v.

2. Then I started the car and it went to about 14.25v.

3. Then I started the car and removed the negative battery cable. The car didn't die. I let it run 5 min. or so.

Seems the alternator and voltage regulator are ok? The battery has a 6/2020 sticker on it so it IS 4 years old and it HAS had a problem where it keeps going dead according to the Seller I bought the car from. SO maybe we're talking about buying a battery here and seeing what happens? With the voltage going up so much while the car is running it makes me believe the alternator is working. How about you?

 

[Super-Cuda]

OK Mike, Here's what I did............
1. I checked the voltage with a meter at the battery with the car off. It was about 12.5v.

2. Then I started the car and it went to about 14.25v.

3. Then I started the car and removed the negative battery cable. The car didn't die. I let it run 5 min. or so.

Seems the alternator and voltage regulator are ok? The battery has a 6/2020 sticker on it so it IS 4 years old and it HAS had a problem where it keeps going dead according to the Seller I bought the car from. SO maybe we're talking about buying a battery here and seeing what happens? With the voltage going up so much while the car is running it makes me believe the alternator is working. How about you?

Go to a local auto supply store (Petboys???) with your battery. They can do a load test on it to determine if its any good. At least you'll know if the battery is the problem

 

[jos51700]

Sigh....Broken Drum time.

the first step when troubleshooting any electrical problem is verifying that the battery is full charged, load tested, and that the connections are in good condition.

Go to a local auto supply store (Petboys???) with your battery. They can do a load test on it to determine if its any good. At least you'll know if the battery is the problem

Beat while typing.

 

[SleeperDart505]

If you have a big electric fan and have not upgraded your charging system, that could be an issue.

It also has MSD 6, a long battery cable to the trunk which draws extra power when cranking, and it has 2 electric fans, one for the coolant and one for the transmission. I think it has high compression but can't be for sure yet. Another reason it may be hard to start. I think a battery with more AH storage would be good as well as more CCA. Would a higher amp alternator help? Would buying a 125 or 140 amp alternator hurt anything by putting out too much?? I mean it could have a 60 amp alternator on there now for all I know. It's an Ultima 01-8152. I tried cross referencing it but couldn't find it. Looks like they sell Ultima alternators at O'Reilley's. I don't have one near me. Since the engine and trans didn't come in this car in 1968, it's kinda hard to look it up without a part number.

 

[SleeperDart505]

Go to a local auto supply store (Petboys???) with your battery. They can do a load test on it to determine if its any good. At least you'll know if the battery is the problem

I did that. Neither auto parts store could get a true load test reading (according to them) because the battery wasn't "fully charged". They both assumed the battery was bad and asked if I'd like to buy one. I have a sneaking suspicion that this is a sales technique to sell more batteries..............

 

[SleeperDart505]

Sigh....Broken Drum time.

the first step when troubleshooting any electrical problem is verifying that the battery is full charged, load tested, and that the connections are in good condition.


Beat while typing.

The battery had been on a Battery Tender for 2 weeks and was fully charged when I drove it 3 miles to the parts store. Is that fully charged enough? Or do I have to take it out of the car and drive it to the parts store?

With the meter showing 14.25v while the car is running, I don't think it was hurting the battery to drive it there. Unless the battery just isn't taking the charge like it's supposed to????

What do you think?

 

[jos51700]

The battery had been on a Battery Tender for 2 weeks and was fully charged when I drove it 3 miles to the parts store. Is that fully charged enough? Or do I have to take it out of the car and drive it to the parts store?

With the meter showing 14.25v while the car is running, I don't think it was hurting the battery to drive it there. Unless the battery just isn't taking the charge like it's supposed to????

What do you think?

It needs to be load tested. A battery with a shorted cell can still read 12.8 volts, but drops to near zero when load is applied.
Sounds weird, but I've seen it myself more than once. Some will have enough juice for lights, but a starter load....nada

 

[Super-Cuda]

I did that. Neither auto parts store could get a true load test reading (according to them) because the battery wasn't "fully charged". They both assumed the battery was bad and asked if I'd like to buy one. I have a sneaking suspicion that this is a sales technique to sell more batteries..............

That's not true . The Auto stores you went to either don't want to test your battery or don't know how.

Any Canadian Tire here in Canada or any Nappa Dealer are equipped to do this.

Also every Car dealership are equipped to do this.

 

[Inertia]

Coupla things.
The jobber was right, you can't get an accurate test on a dead battery, it needs to be fully charged before testing, and I'm not sure if a trickle charger could charge a dead battery sufficiently.
They may have wanted to "charge" it properly first, we would.
Hydrometer test prob not.
If you can, charge it properly overnite, - take it back and tell them it's got all the charge it'll take, load test it . .
jmo

 

[SleeperDart505]

It needs to be load tested. A battery with a shorted cell can still read 12.8 volts, but drops to near zero when load is applied.
Sounds weird, but I've seen it myself more than once. Some will have enough juice for lights, but a starter load....nada

Thanks. I didn't know any of this.