Technical Electrical problem that is soundly beating me

Car in question, '64 thunderbird, 390 BB.

This story takes place over several weeks so bear with me.
First, driving and I notice lights are a little dim, or are they?
It's dusk, eyes are probably just playing tricks on me. Stop light,
cars running a little rough, or is it? fast forward two miles to
me on the side of the road with no voltage. Now, I run an Optima
battery and I know they can discharge and die in unpredictable ways
(not unlike this). So I get a jump and limp it home. First off, check
and clean all grounds even remotely related to charging system, No go.
Take battery and alternator to NAPA, both test out fine. I automatically jump
to the voltage regulator conclusion and just replace it while I'm at NAPA.
Thats not it. This car has way more wiring than I care for and to make
matters worse they are all bundled into one huge, seemingly, circular harness
that does a lap around the perimeter of the car. My thoughts are that something
has shorted in one of the 4 wires going to the voltage regulator but I really
don't want to break open that big-ass harness so as a test I wire it up single-
wire style and everything is running and charging great until I turn the car off.
Then I just watch the volts drain out into the ether. I try another battery that
I know is good from another car, same thing. So, still not wanting to cut open
that wiring harness, I decide to rewire to the voltage regulator with all new
wires and leave the originals in place but disconnected. Seems successful in
that it runs, and charges however, again, turn the car off, and watch the voltage
drop by about a volt an hour till it dwindles to nothing. I think, maybe I have an
internal short in the alternator at the field post, so I replace the alternator, Nope!
Here's the weird part, If I disconnect the "Field" wire on the back of the alternator
(In either single wire or externally regulated scenario) voltage stops dropping.
What am I missing? Please, feel free to cuss, swear and berate me, as long as you
offer some useful info in return.

Thanks in advance.

 

So....you have a volt meter, right? you know how to measure voltage, because you said the battery voltage keeps dropping, right?

Looks like 64 was the first year of alternators on Fords, only on some models. You are sure you have an alternator, not a generator? and the voltage regulator is the correct one for an alternator?

 

Yes, to all of the above questions.
That diagram is better than any I was able to find online
(the manual is impossible) So thanks for that and the quick reply.

 

I would pull one fuse at a time and see what circuit the drain is on. After that I would check the key switch, headlight switch, horn relay, glove box light on? trunk light on?, etc. Turn everything off and check the ignition system for being live................................

 

Remove the cover from the regulAtor, And run the motor, then turn off. Give the regulator A "tap" on the side and observe what the points are doing. If one opens, it looks like the points are sticking closed after power is turned off. Sometimes just cleAning them (be careful not to Alter the gap) will fix it.

 

I have had this same trouble with an O/T racecar. Diode failure was my culprit which would cause voltage drop (and an eventual dead battery) when the engine was not running, but would charge the battery when running. With the engine off (obviously) remove the charging positive from the alternator post and check resistance to ground from that post. If you get anything other than infinite, there's your drain.

 

and with the battery disconnected

 

Pulling one at a time while using a light is the way to find a parasitic draw. It's the process of elimination that needs to be used.

Or pull them all first, to elimate fused circuits. If there is still a draw it's not in the box. If no draw add them back one at a time till draw shows up.

 

If you have way to many; I would just start chasing loose ends.
And check plus side, visual the the way you did ground.

But a new harness 9 out of 10 be easier, faster and cheaper!
According to my first boss, the only time in a automotive history that this 3 comes in same sentence, and it dosent end with; pick one(!) Is when you change to a full pre-assembled wirring harness.

 

Ugh... choosing between hari-kari and installing a '64 Bird harness would be a tough choice...

 

I choose "Hari Krishna". Because I'd rather shave my head, put on an orange robe and chase people through an airport asking for money than tackle a T'Bird harness...

 

What make an bird this bad? Compared to chasing a gremlin on an infinite loom full of hidding places?

 

I guess you never worked on one of these cars. I have.

 

I bought one of those Hari-Krishna books at the airport when I came home from overseas. Seemed like a nice bunch of kids. Come to think about it I may have traded them something.

 

Hari-Kari And hari-Krishna are not the same. Back to your regularly scheduled problem.

 

If the I wire going to the regulator comes from the ignition switch, then the ignition switch might be the problem. I would check the I terminal on the regulator with the voltmeter. If it reads any voltage while the ignition switch is off, then ignition switch might be defective. Post the voltage readings.

 

chasing wiring gremlins can be overwhelming and scary but squirrel got you a nice diagram take your time and familiarize your self with the circuit it should become simpler the more you familiarize your self with it and test both ends of the wires to know what is" entering and exiting the wire " this is usually overlooked when I help other techs find problems at work . take your time you will find it.

 

Nope but I worked on cars from 1960-2000, that had more yards of extra useless wirring the my body has feets of small intestate. And has fewer working ligths then a Model T, despite having three time the lamps and four time tge gizmos. I even worked on British wirring and Italian wirring. They both battle in the worst electronic junk in modern history.

Why is a bird that bad? I bet a sunliner is worth?

 

Similar thing happened to my Mom's big, old Plymouth. Turned out to be that someone had put something large in the trunk and knocked the trunk light tab out of adjustment. The trunk light would stay on and drain every battery I tried. Came home late one night to see a little, round ray of light under the car. Luckily, a trunk plug had come out and so the light shined down onto the driveway so that I was able to discover the problem. Had the plug not come out, the car would probably still have that problem.

 

OK, I'll throw a few more thoughts into this....

Does this car have an idiot light or an factory ammeter? While the alt/regulator are the same, they're wired differently. Jim's diagram is for the idiot light version.

You stated you connected the alternator as a 'one wire'. Exactly how did you do this? The only way to do this is to run the alternator unregulated at full output, which isn't good for either the alternator or the wiring for more than a quick test. A partially failed diode can cause a draw yet still charge; to fully check this, the alternator has to be disassembled.

Make sure you have near-zero resistance between the regulator base, the alternator case, and the negative battery terminal. Make sure you use a low-ohm resistance setting on your meter; if you're using an audible 'diode' setting, that merely indicates that you have continuity. The display is actually diode 'pass-through' voltage, not a resistance reading.

If you're getting a current draw with everything off, try disconnecting everything off the battery side of the solenoid, then connect each wire one at a time. One wire will be the wire to the alternator battery terminal, one will be to the ignition switch, and there probably will be several more for various power accessories (these will very likely have circuit breakers installed in line). This will at least isolate the draw down to a sub-harness.

 

As I mentioned in my super long-winded opening explanation, the problem lies somewhere in the Field circuit. With the car off, voltage drops at a visible rate via my meter. As soon as I disconnect the field wire from the regulator or the alternator the drain stops. However, I have replaced, alternator, voltage regulator and field wire to no avail.

If, however, I use the original wires in their original configuration this drain does not occur but the battery doesn't get any charge. I'm beginning to think I purchased a faulty Regulator.

 

Your not listening, good luck on the problem and fill us in on what you find.........................................................................
On another note, it used to be that you had to polarize the voltage regulator in order for it to work, maybe that isn't true anymore with todays parts?

 

Generators need polarization, not regulators.

Technically only if they have been disassembled, or have perhaps sat for a very long time. Somehow people sometimes think that simply disconnecting the battery means polarizing is necessary. Not only incorrect, they often use the Ford or type "B" method on a Chrysler or whatever, and roast something.

 

Interesting topic. I too had a "64" Bird. When I had the dash out to chop the top, I thought I'd clean all the gauges. The ammeter guts looked as if it got really hot. Occasionally at night the lights would get really bright and then settle down. I'm not sure what was going on. I put after market gauges in and used a volt gauge instead of the ammeter. No more problems. Sold the car, but I'm still not sure what was going on.

 

I am listening, I've just tried most of the ideas suggested prior to my original post, including your's, Brigrat. Thanks for the suggestions, everyone.

.

 

I will say that some of those aftermarket 'electronic' voltage regulators for early Ford alternators can be crap; I've seen three bad new ones in a row from a parts house before getting a good one, so you might try another one from another source or brand.

 

Maybe install a one wire alternator? They make a Ford style but I don't know how it compares to the original.

http://www.cvfracing.com/Ford-1-Wir...085_a_7c2128_a_7c8596_a_7cFORD_d_1WIRE_d_100A

 

Engine Man, Awesome, thanks, didn't know those existed.

 

I am running one of those on an off topic SunBeam Tiger with a Ford 302. Left the regulator and wires there to look factory but not used. Been running for years with no problem.......................

 

Crazy Steve, thats where I'm at now, going to a buy an old style mechanical one tomorrow. What was on there and what I replaced it with is the newer, printed circuit type.