Faulty battery, bad alternator, or both (photos)

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I do a good job mixing up my explanations! I should have just left the part about the amp bypass modification out of my post (I have checked this circuit and it tests ok)

One thing that did throw me off initially was, the diagram below shows the wire going from the splice to the ignition switch as a "black" wire.
Actually, the wire that comes off the splice and goes to the ignition switch becomes the RED 12g wire for the ignition switch.
I verified this with my wiring diagram and with the harness itself because it really confused me.

I think you hit it on the head with what i've quoted below though. I was talking about the ACCESSORY black wire not having continuity.

The path for this wire is:
Big Black Wire FROM Ignition switch TO Second buss in fuse panel.....also.....
Big Black Wire FROM Ignition switch TO welded splice with 12g Pink wire TO Wiper Switch.

(I can take a photo of my wiring diagram when I get home if I'm still not making sense...)

67Dart273 said:
ACCESSORY (black)

This big black wire comes FROM the ignitions switch and TO the accessory buss in the fuse box

The SECOND buss in the fuse panel is your "HOT" buss and this comes direct from the splice to that fuse buss.


=============================================================================

What is not shown in the diagram below:

Ignition switch and feed from switch to "switched" accessory buss in fuse panel

They do not show the wiper feed, I'd have to check that. Yours comes off the splice?

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Click to expand...
 
UPDATE:

I just ran through all of the tests and got signs pointing to no short, from the harness.

Went to start the car and the ignition wires at the alternator were hot *** hell and the car wouldn't turn over.

I then remembered 67Dart273 told me to try WITHOUT the alternator hooked up. I unplugged the field terminals, unplugged the VR connector, and unplugged the alternator BAT cable. Went through the motions and voila - the car started.

Does this mean (as someone else mentioned) the alternator itself is shorted out?
 
"Hot as hell" points to a short. WHICH wire / wires was / were hot?

If it's the small field wire, you probably have a shorted brush holder at the alternator or a shorted field.

Easy. Unplug both field wires

Set your meter for resistance.

Hook one probe to either field wire, the other probe to ground. You should read an open, or infinity

This could very well be the original problem.
 
That was it!
Field was shorted. Already went and got a new alternator, put it on, tested it like you said and now got a reading of infinity.

Wow. What a roundabout assed way to test a bad alternator. Haha.

Oh well, at least I learned A LOT about wiring!

Thanks for your help Del.

You're very knowledgeable about all of this and folks on this board are lucky you're a member!
 
Happy for ya

"We" used to get rebuilds occasionally that had the wrong brush or wrong brush hardware, and one would be grounded right out of the box

You had a 50-50 chance.......if you hooked the blue field wire to the faulty one, you had "your problem" if you hooked it to the other one, it would simply overcharge like mad
 
I owe ya' one. :)


Confirmed the new alternator is actually charging:



And I bought this temporary volt-cigarette-plug-o'meter for $6. Surprised at the accuracy!

 
OK after you take a deep breath, let's check that out...........if your engine / battery was warm when you took that, it's "a little high." Not too bad but a little

Might be voltage drop in the harness, or a poor ground on the regulator.
 
Del,
I took your advice and tested for voltage drop (I saw you posted instructions in another thread).

With the car running at fast idle and nothing on, the voltage from NEG BAT post to VR flange is .01

I then turned the car off, left in RUN, and checked voltage from the blue field wire to the POS BAT post. Result was .10
 
Saverio said:
UPDATE:

I just ran through all of the tests and got signs pointing to no short, from the harness.

Went to start the car and the ignition wires at the alternator were hot *** hell and the car wouldn't turn over.

I then remembered 67Dart273 told me to try WITHOUT the alternator hooked up. I unplugged the field terminals, unplugged the VR connector, and unplugged the alternator BAT cable. Went through the motions and voila - the car started.

Does this mean (as someone else mentioned) the alternator itself is shorted out?
Click to expand...

That was me in Post #15...... Lol Glad you got it fixed you did a lot of work and testing..... Damn you are a trooper and a calm one at that!

Mad Dart; Sounds like the Alternator has a Dead Short in it.

Damn, you guys almost burned his car to the ground! ..... Lol, just messing!

I had a battery in one of my old little pick ups that popped out of the battery hold down and the + side hit the hood and grounded.... Burnt my whole harness all the way to the firewall. Nothing like a broke kid re wiring the complete under hood on the side of the freeway! haaaaaa
Click to expand...
 
Thanks Mad Dart.
I may seem calm in my posting, but that's just because I've had time to cool down. Lol!
Thanks for your advice!!!
 
Saverio said:
Del,
I took your advice and tested for voltage drop (I saw you posted instructions in another thread).

With the car running at fast idle and nothing on, the voltage from NEG BAT post to VR flange is .01

I then turned the car off, left in RUN, and checked voltage from the blue field wire to the POS BAT post. Result was .10
Click to expand...

This is troubleing, because this "looks good." Yet your charge voltage is some high. I would try following. Run the car for awhile, let the battery sort of "get normalized." You likely have been running it up/ down with all the testing and so on.

With the thing run long enough to have the engine / battery warm and "normalized," lights off, etc, recheck your charging voltage in another week or so of driving. If it's still high, I'd try another regulator

The only other possibility I can think of is.........bad connection at the VR connector

In RARE cases the battery can cause this

and..........you might "double check" your meter accuracy
 
Del,
Could a bad ballast resistor cause the high reading I am seeing?

I saw on mymopar that the top side of the ballast resistor should be 5ohms and the bottom side should be 1.2ohms.

http://www.mymopar.com/index.php?pid=115

I'll go double check now, but I don't remember mine spitting out those ohm readings...I think mine were lower on both accounts.
 
The ballast doesn't have anything to do with charging voltage, if that is what you are asking

Also, ballasts don't "generally" change resistance enough to cause trouble. They are usually either OK and work, or burned open. This is simply because of "how they are made" They are wirewound resistors made of resistive (nichrome, etc) wire
 
67Dart273 said:
The ballast doesn't have anything to do with charging voltage, if that is what you are asking

Also, ballasts don't "generally" change resistance enough to cause trouble. They are usually either OK and work, or burned open. This is simply because of "how they are made" They are wirewound resistors made of resistive (nichrome, etc) wire
Click to expand...

Ah, I see. Thanks for the info. I'll give it a little more time (I've only drove it today since getting it running again).
 
I would suspect that multimeter, as well. Friend of mine has one / similar, and it's not accurate. I've seen several others that are OK
 
Well, add another one of these multimeters to being a "problem".
It WAS free at Harbor Freight, I guess I shouldn't be too surprised.

I stopped by my work and borrowed our Fluke meter. I trust this one because it's calibrated frequently.

It's charging at ~14.2



I guess I'm in the market for a wired voltmeter. Which one do you use/suggest?

Thanks!
 
Look on ebay and buy a used Fluke? Or buy a new one?
 
67Dart273 said:
Look on ebay and buy a used Fluke? Or buy a new one?
Click to expand...

Oh I meant a "gauge", for inside the car. LOL

I saw a great thread on here about folks using a Sunpro in place of the ammeter gauge. I was just curious what you use....
 
67Dart273 said:
OK after you take a deep breath, let's check that out...........if your engine / battery was warm when you took that, it's "a little high." Not too bad but a little

Might be voltage drop in the harness, or a poor ground on the regulator.
Click to expand...

Rather than start a new thread - I thought I'd continue this one....

I'm still seeing the alternator charging a little high (14.7-14.9), as Del suggested, so my question is: would it do any harm to add a ground jumper from the voltage regulator to the ground strap?

I actually think that's where i'll start, the ground strap. Last I looked at it, it was covered with grime.
 
I'll have to review all this to see what you did. A ground strap CERTAINLY cannot hurt. The VR must be at same voltage "at the ground point" as the battery NEG.

"How I did" mine

Look on your passenger side head at the alternator mount. Those same bolt holes are available at the REAR of the driver side head Go to the parts store and buy about a 1 ft long "starter" cable. These are "eye to eye" ends. Get a short bolt, reach back there and hook that cable to the head, bend it down to a "U" and come up and either put a sure bolt through the firewall some place or in my case I used one of the master cylinder studs.

Make SURE the VR is scraped clean as well as the firewall, and get yourself some star lock washers to mount the VR. Doesn't matter if they are internal or external


lockwashers.jpg
 
Hey Del,
Just wanted you to know the outcome of this.
I took your advice and added the ground, was still getting crazy overcharging (14.5 jumping around to 15.2) as soon as I started my car up - and, a new problem, the headlights would get brighter every time I hit the gas.

Checked the voltage from the IGN wire at ballast + BAT Positive post and was getting a tenth of a volt. All good there.

I started reading through some other posts about bad grounds and saw someone post about their ECU mounting area being painted over.

Never thought about that one! Went out and checked mine....sure enough, nothing but a thick layer of paint underneath.

I sanded the mounting area down to bare metal, reconnected everything and boom, now a steady 14.5 volts - also, the headlight issue went away.

No more jumping around and everything seems to be charging ok.

Does this sound right? Any other connections I should check?
 
67Dart273 said:
You need to follow what "melted." Those are your clues

Let's say power comes FROM the bulkhead on that ignition "run" feed and goes to the choke. Is it melted UP TO that point? Where does it branch off and go to FROM THAT POINT? If it uses that terminal as a junction and feeds from there off to the alternator and it's melted up to the alternator, then the alternator is a suspect

I "hope" you did not cause this in your testing. The blue alternator field wire is in that circuit. That blue field wire feeds power TO the alternator field. If that should become shorted, either because of something you did, or something wrong in the alternator, it could easily have caused that damage.

You have to go "back in time." Up until "smog stuff" there was not much stuff "under the hood" which the blue ignition FED

About all on my original 67 was the ballast and the VR IGN terminal. This is before the new style isolated field alternators, and before electric chokes, or any other smog gear

I guess Ma figured "it was worth the gamble." The original regulators had a "sort of" fuse built in. It was not replaceable, but it would blow out and protect the harness, and if lucky, would allow the car to run and limp home. What I'm saying there is "example" as in a problem / short in the alternator field.

BUT if you did "something" like say, allow the harness to become abraided, worn, bare wires, and short "on the body" ETC, then you could easily burn down the harness.

Now this happened to ME

In the early 70's some girl a-holed my 70 V code RR. While it was being ("fixed") by McCune Chrysler Plymouth in National City, and I do mean "fixed" the insurance co. lent me a loaner car, a beat up 70? Valiant.

One cold morning I started the car at the RADAR shop, let it warm up. My leading Chief, who was ALWAYS doing an impression of Columbo, came into the shop

"I have a question, just one question?"

"Yeh, Chief?"

"Is that loaner car of yours, is is supposed to squeal and smoke under the hood??"

So I go out there, and the alternator is STOPPED. Except the engine and belt are still GOING.

So I shut it off. I get a wrench and a rag. I loosen the belt, and I wiggled the thing for no good reason. And HERE is what happened, "follow along."

It TURNS OUT that a DIODE had fallen out of the frame of the alternator and down inside and STOPPED the alternator. But it had not SHORTED. BUT........LOL.......the WIRE was still connected. And when I came along and wiggled the damn thing, I got to stand there and watch the underhood harness go sssss.s.s.s..ssssssssssssssssss...ppphhhhhhhhhiiiiiiisssssisisiisishitssssssssssshitssssssfffffphphssssTTTT!!!!

And after it got done, the fuse link went "!!phft??!!" and blew out.

It was a mess. A smoking, black, smelly, smoldering mess. And now, I had no car

So I called the dealer, and I said to them, like this:

Send a wrecker out here, and send out another loaner car, because the underhood harness just completely burned up.

So they sent out the green card holder who could barely speak Heenglessh, in a beat up pickup with a set of booster cables.

And he looked under the hood. And he says to me, like this:

"Theese theeng won't run..........ees all burnned up een there!!!"

So I got to wait ANOTHER two hours while the dealer "sent out a wrecker" and "sent out another loaner car."

Hell I could 've had the thing half rewired by the time I got out of there, and it was my day OFF!!!





81sruds.jpg
Click to expand...

Good info. YOU are well versed in MOPAR wiring, I thought I was a PRO, but you have a very good grasp of how they put these early MOPARS together. Hears to you:cheers::cheers::cheers::cheers::cheers::cheers: MT
 
Saverio said:
Hey Del,
Just wanted you to know the outcome of this.
I took your advice and added the ground, was still getting crazy overcharging (14.5 jumping around to 15.2) as soon as I started my car up - and, a new problem, the headlights would get brighter every time I hit the gas.

Checked the voltage from the IGN wire at ballast + BAT Positive post and was getting a tenth of a volt. All good there.

I started reading through some other posts about bad grounds and saw someone post about their ECU mounting area being painted over.

Never thought about that one! Went out and checked mine....sure enough, nothing but a thick layer of paint underneath.

I sanded the mounting area down to bare metal, reconnected everything and boom, now a steady 14.5 volts - also, the headlight issue went away.

No more jumping around and everything seems to be charging ok.

Does this sound right? Any other connections I should check?
Click to expand...

14.5 is on the ragged edge of "high." If it doesn't go any higher, watch the battery a few weeks for abnormal bubbling, acid, etc. If not, "call it good." I guess you've read the infamous "Mad Electrical" article. It does a good job of "why" these have problems. Whether in the bulkhead or other connectors, it really gets down to terminals and switches.
 
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