Nah, no need to panic. Looking at your meter, it's set to a 20VDC scale. The .01VDC displayed is at the very, very bottom of that scale. Some quick math shows it is only .05% of full scale. Hardly any meter is accurate at that tiny percentage of full scale.

Switch to the 2V scale for any future voltage drop tests and you should be fine.

In your latest post, with the original direct-drive starter reinstalled and the battery fully charged, you said all is well so far. You can run another voltage drop test on the cables if you want using the 2V scale, but for now, I'd suggest concentrating on the battery state of charge before each start. Monitor the charging system and make sure it's not intermittently dropping low while driving.

Does the 3G alternator use a voltage regulator attached to the inner fender? If so, run a dedicated ground wire from the regulator base. Don't rely on the inner fender to provide a reliable ground. This is a known weak point in the charging circuit.

If you don't want to get a dedicated plug-in voltmeter for the lighter socket, you can get something like this Lisle 32150 and connect your regular voltmeter:

 

My thoughts are yes this has been a leviathread but we've come too far to stop now. Good luck OP we will see this through.



(The only times I was melting solenoids and they would stick until I got out and rapped on em...it was my battery cables....changed them wire wheeled ground contacts on the frame.... good to go...)

 

So far so good. Didn't have slow crank at least 8 times I tried, battery seems to be fully charged now too. I will put in my socket plug tomorrow to monitor voltage and play it by ear.

the only downside to all my experiments today is that I changed multiple variables, and wasn't able to pinpoint the exact location of the voltage loss. The old direct drive starter seems to have no problem cranking the engine, and it seemed to be happy with its voltage but again, the battery was fully charged by a wall charger, and this we know doesn't seem to be the problem. It seems that keeping the battery topped off while driving is the key. Whatever variable that takes will be my answer.

the alternator itself is internally regulated, and is wired accordingly, I haven't dried the solenoid yet, and that seems to been an impeding doom I hope to solve by installing the motorcraft unit tomorrow.

 

Agreed, I think you are hot on the trail trying to isolate why the battery isn't staying topped off while driving. Keeping a voltmeter on hand should go a long way to determine what is happening.

At the risk of repeating myself (actually, this has never bothered me...), run the AC ripple test on the alternator. It will only take a couple of minutes. Be sure to connect your meter right at the alternator, not at the battery. You'd think it wouldn't matter, but it does. The red lead goes on the big output terminal. The black lead goes on the alternator case. Set the meter to AC volts. Try various combinations of RPM and electrical load. Anything more than 0.5VAC indicates a bad diode. From your pics, I see the lowest ACV scale on your meter is 200. You may want to borrow a different meter that has a lower scale so you can reliably discern 0.5VAC.

Also, do you have a dedicated ground from the alternator case to the battery's (-) terminal? This will help increase reliability.

Good plan on replacing the Chinese starter relay with a Motorcraft, too.

 

One more thought: Test the alternator output (AC ripple and regular DC) both cold and hot. There could be a bad solder joint, for example, and thermal expansion could either open or close it. To test cold, run the checks immediately after start, minimal electrical load, first thing in the morning. To test hot, go for a long drive with maximum electrical load. Won’t cost anything but a little bit of your time.

 

I'll do the ripple test tomorrow.

is the case of the alternator grounded to the meg side of the battery? Yes and no. Not directly, but the block is grounded to the battery and it's bolted to the block.

 

 

It seems the resolution may soon be at hand. As this thread winds down and approaches 200 entries, there's still one more important detail that needs to be addressed:

Blame

Who is responsible for not diagnosing the fault earlier?

It's time to implement my patented BlameShifting(tm) protocol. What if I had said unequivocally, "Your xxx is bad" and then $200 later, the fault is still there. I'd have to hang my head in shame. That's why the prudent BlameShifter(tm) says, "Read these other threads or consider this, and then decide for yourself." Thank me if I'm right, blame others if I'm wrong.

Amateurs try to minimize it, but blame is insidious and never diminishes. The best you can do is ruthlessly minimize "Time in Possession" and toss the hot potato to somebody else.​​​ When BlameShifting(tm), one must also vigorously stay alert for the BlameBoomerang(tm), which is self-explanatory.

These basic principles will serve anybody well in all aspects of life, especially at work. And now Grasshopper, you must take this pebble from my hand...

 

 

Two ways to proceed from here. Both methods require starting with a fully charged battery, so hook up your charger again.

The simplest method is to disconnect the battery overnight, after it has been fully charged and the charger removed. If you had a parasitic drain, it can't discharge a disconnected battery. If the next start is normal, you'd know the battery is not self-discharging and something external is running it down.

The more involved method is to run a parasitic drain test. Here's a good video describing the process. It's long but full of good info:




One minor gotcha was not mentioned in the video. The test of pulling fuses individually is only going to find a fault if the drain passes through a fused circuit. Some faults, such as a leaky diode in the alternator, will still be present with all fuses removed. So if you determine a drain is present, but pulling the fuses doesn't stop it, the fault lies in a non-fused portion of the electrical system.

 

I agree that checking for parasitic drain is a good idea. But he is not losing enough voltage to warrant a hard start issue.


I think it might be time to look at the possibility of the battery being faulty. It is going to need a proper load test for find out for sure.

 

That's crazy talk! Let the saga continue for another 20 pages...

 

One possible fly in the ointment: Could the 12.57V displayed include a surface charge? The true voltage (and state of charge) may have been much lower. Just thinking out loud...


Was the battery load tested at the parts store? See post #177.

 

Hear! Hear! I second the motion! All in favor say, "Aye!"

Why, we've barely scratched the surface. What of electron theory? Which way do electrons really flow? AGM vs. flooded cell? 1G vs. 3G? The list goes on...

 

If the battery is faulty either internal short/leak or reduced capacity the surface charge would dissipate quite quickly as it would be drawn by the fault in the battery. Now if it was just reduced capacity due to age then yes it could. But the battery is new so this is unlikely.

Most all new battery testers are conductance testers. They will in 99.9% of the time uncover a bad battery.

But there are instances where they will not. An example being a short or break that does not appear until the battery is actually loaded and heated up so a thermally induced fault is produced, reducing available voltage/or amperage depending on the type of or where the fault is occurring.

In these instances the battery needs to be load tested or a loaded conductance test, and not just conductance tested.

A reduced voltage fault would explain the slow crank and high amp draw. As voltage is reduced more amperage will be needed to do the same amount of work .

At this point the battery needs to be checked to ensure it is functioning as specified.