Hi folks, I've got a 62 Dodge Dart with a 318. The other day it wouldn't start after sitting parked for only a few minutes and having no previous similar issues. It jump started very easily. I drove it ~5 miles home. An hour later it wouldn't start again. Having previously noticed black on the alternator I assumed a bearing went and got a new alternator. I installed it and jumped it but that didn't fix it. I jumped the car and disconnected a battery terminal and it stalled. I then bypassed the voltage regulator, jumped the car, disconnected a battery terminal and it kept running. I've since tried 2 new voltage regulators and neither fixes the problem. I've tested every wire from battery to starter to volt regulator to alternator and all read 0 ohms. I called AAA to see if it was their 3 month old battery I had bought from them. They came and said the battery looks fine but had no signal coming from alternator. Any ideas? Each of the following is less than 3 months old and was until now working fine: battery, battery cables, engine block ground, starter, voltage regulator, alternator, plugs, wires, cap, rotor, points and probably a couple other things I'm forgetting. And help would greatly be appreciated. Thank you

 

First, DO NOT EVER remove a battery cable from a running engine. On later vehicles with more electronics, it can damage or fail electronics, and besides, it proves NOTHING. You will never see this so called "test" in any shop manual, Motor's manual, or taught in any auto class

Why? Because, if the charging system IS working properly, and if you happen to have the engine idling slow enough, the alternator may not be putting out enough to "pass" the test, even though the system is OK!!

AND, if the alternator has a bad winding, or some open diodes, you may have a 30A alternator than only puts out 10A, etc. And if you remove the cable in this case, the damaged alternator may put out enough to run the engine, thus "passing" the test with a bad alternator!!

Get yourself a test lamp and a digi meter. Get yourself a shop manual or at least a wiring diagram.

From here:

http://www.mymopar.com/index.php?pid=31

Not the correct year service manual, but the charging systems were the same from the first alternator in 61? 62? until the end of 69. 70 and later use the "isolated field" alternator and so 70/ onwards are different

http://www.mymopar.com/index.php?pid=109

Useable wiring diagrams for your car

http://www.mymopar.com/downloads/196...rtPolaraV8.JPG

You can also use a 70/ later isolated field alternator with your early regulator, simply by grounding either of the two field terminals of the alternator. These are often incorrectly called "dual field." The correct term is "isolated field" (isolated from ground)

So make some tests.

Pull the field wire off at the alternator. Get or make a clip lead long enough to reach either the battery or the big stud on the starter relay Connect this jumper to the field terminal and to the battery. You should get a small spark, if lighting is dim.

Start the car, observe the ammeter, and see if slowly increasing RPM results in a charge. Be careful not to go "nuts" because this is known as "full field" and causes the alternator to produce max output. If you are not careful, you will cause an overvoltage situation, and can damage components and blow out light bulbs. It is SAFER to rig your meter to the battery, prop it up so you can see it, and watch and keep the voltage below 15.5, below 15 if possible.

IF NOTHING above, with the engine running, move your voltmeter to the output stud of the alternator. See if increasing RPM causes an increase at the stud. If the voltage here DOES climb rapidly, and NOT at the battery, you have a break in the charging buss from the alternator output to the battery through the firewall and ammeter circuit.

If you do NOT see an increase voltage at either the battery OR the output stud, and if you are certain that you have battery power at the field terminal (check with your meter) then the alternator is bad. (New does NOT mean "good.")

If you DO see a voltage increase at the battery, IE charging, you have a bad regulator, or a wiring problem in the field circuit.

Reconnect the field terminal. Disconnect the regulator, and jumper the two wires off the regulator together. This will feed "ignition run" or "switched Ignition" voltage coming from the ignition switch, right to the field, just as you did previous

With the key in "run" engine off, check the voltage at the "key" side fo the ballast resistor, and again at the field terminal of the alternator. This voltage should be close to battery voltage.

Again start the car, and slowly bring up RPM. If the first test (jumper to battery) showed a charge, this one should too.

If not, you probably are not getting ignition "run" voltage to the regulator. You should have already checked this above, so if this voltage was low or missing at the alternator field, you may have a broken wire/ end terminal in the green field wire.

If you don't have voltage at the regulator IGN terminal (where you hooked the wires together) then this is a very short wire -- it junctions to the coil ballast resistor.

The diagram is a little difficult to follow, but the "dark green" from the regulator is one simple wire which goes directly to the alternator field

The "dark blue" at the regulator is "switched ignition" or "ignition run" and junctions at the coil resistor, then runs through the bulkhead connector to the ignition switch. There is no fuse in this circuit.

If voltage is low at the regulator or coil resistor, suspect the bulkhead connector damaged, or the connector on the IGN switch, or the switch itself

I'm not sure what your old girl does in the form of getting the charging line through the bulkhead -- some of the older cars had separate feedthroughs and did not use the bulkhead connector (big black from alternator to bulkhead, and big red from starter relay to bulkhead)

Depending on how these two large wires are fed through the bulkhead, THEY can be a big suspect in this problem.

Last, the ammeter itself, and the "in harness splice." THAT'S RIGHT a factory splice in the under-dash harness. To see this in the diagram, find the ammeter, and follow the black wire straight up the page just before it turns left. There are three wires coming off this black. One feeds the IGN switch, one feeds power to the headlight switch for headlight ONLY power (not tail or park) and the third feeds the "hot buss" to the fuse box.

So if the above tests showed a charge, you are right back at the regulator. The regulator MUST be well grounded.

Post back with results, and we'll go onwards

 

Hi Monkeyman and welcome to the forum!

Lots of good information here and this is actually a very friendly site with some great people with a lot of knowledge!

I did a quick search and found a wiring diagram for your Dart to help when you test your system.

We'd love to see pictures of your car!

Rick

 

Thanks for the welcome to this forum and 440Roadrunner thank you so much for such fast, detailed and helpful advise.

I'd gotten to where I was testing voltage between alternator field and key side of the ballast resistor. It read greatly lower voltage which actually DECREASED when I increased the RPM. Standing there scratching my head and just looking around I saw the problem. This dumb monkey somehow reversed the wires when I installed a new ignition coil about 10 days before. I'd driven it like that maybe 20 miles and I guess that's all I was able to pull off the brand new battery. I don't know how I wired it wrong and I don't know how the ignition coil even sparked like that. She is running like a champ now!!!

Now that she's running better than she ever has since I've owned her (5+ years) I can start thinking about paint. Thanks again guys! I hope someday to be able to return the favor. I'll post pictures soon.

 

OK, so you are saying that you had the regulator hooked to the coil side of the ballast?

Now, I'd like you to do some additional tests

Please start by reading this article by Mad Electrical, which details the problems with Mopar bulkhead connectors:

http://www.madelectrical.com/electri...p-gauges.shtml

came from this page:

http://www.madelectrical.com/

Again, it is not clear to me whether on your car, the charging line and the main battery feed actually go through the connector or through a separate feed-through, some of the earlier cars did that.

In any case be aware that a damaged, corroded bulkhead connector can introduce "voltage drop."

So check your system for this drop

1 With engine off, and key in "run" position, first determine if the points are closed if you run a breaker point dist. Put your meter on the coil NEG terminal, and to ground. IF you read near battery voltage, the points are open. Bump the engine, until the voltage goes to a low value

Next, stick one probe of your meter directly onto the battery POS post. Stab the other probe on the "key" side of the ballast, or onto the regulator IGN terminal. You want your meter set to low DC volts, and you are actually measuring the voltage drop through the harness.

The basic circuit path is battery -- fuse link -- bulkhead connector -- ammeter circuit -- igntition switch connector -- through the switch -- back OUT the IGN sw connector on the dark blue "run" wire -- back OUT the bulkhead connector to the IGN buss at the key side of the ballast

What you are hoping for is a VERY low reading, the lower the better. Anything over .2V (two TENTHS of a volt) is cause for concern, anything higher, get in there, read your diagram and the MAD article, and find out why. Your number one, two, three suspects are the bulkhead connector, the ignition switch connector, and the switch itself.

2. Next, check the ground side of the charging circuit. Start the car, get it on fast idle to simulate low-medium cruise, and let it warm up. This is because you want the regulator warm to stabilize battery voltage, and also, you want the battery "normalized" IE charged up. Normally, your ammeter will be centered when this is true

Stick on probe of your meter directly onto the battery NEG post, with scale set to "low DC volts" as before. Stab the other probe onto the metal mounting flange of the regulator, and be sure to stab through any paint, rust, chrome.

Once again, you are hoping for a very low reading, the lower the better. Over .2v means the ground between the battery, block, and body is not good enough

3 Last with the regulator warm, the battery charged, and the engine RPM simulating low/ med cruise, check the battery voltage right at the battery posts. There is some argument as to the high / low limits, but your pretty much want optimum of 14V Anything below 13.5 or above 14.5 is cause for concern.

IF you fixed any problems in 1 or 2, and the voltage is high or low, have the battey checked, clean the battery terminals, and make sure the regulator is up to temperature (warm engine bay.) If the voltage is still off sustantially, make sure the alternator is capable of good output (with the "full field tests mentioned previously) and if none of this leads to a cause, put a new, good quality regulator on. The "higher priced" NAPA (VR-1001) and Standard Blue Streak (VR-128) are considered good

 

440roadrunner, again thanks and WOW I can't get over the depth of your help!!! I will take those readings maybe, hopefully this weekend.

What made you think I had the voltage regulator hooked to the wrong side on the ballast resistor? I don't think so, but maybe....I'm open to anything. What I found is on the ignition coil itself I had the wires backwards ie lead to - and + to distributor.