I thought everyone had 2 of the commercial chargers like this?

Both of mine are from the 80's
Dave ----

 

Agreed on the need for load testing. As a tool geek, I've got both an old school load tester (aka toaster) and a new-fangled conductance tester. Each tells different sides of the same story about a battery's general condition.

However, when we talk about the importance of load testing, the downside is very few shadetree mechanics have either type of tester. Sure, you can take the battery to the parts store and have it tested, but there are two serious drawbacks to that:

1) Inertia. It's a nuisance to remove the battery, haul it to the store, haul it back, and then reinstall. Meanwhile, you just lost all your stereo presets, including that new all Bee-Gees station (BTW, they were NOT responsible for disco, predated that dark era, and i will defend them to my last breath).

2) It's tough to objectively believe the pimply-faced kid paid on commission who insists you need to replace your battery.

That's why my long-winded test procedure includes a poor man's version of the battery load test:

https://www.ford-trucks.com/forums/1...w-starter.html

Instead of using an actual load tester (new or old school) to make the battery work hard, the test uses the next best thing: The starter.

The starter is the most severe electrical load found on nearly any vehicle. An electric winch might draw more current (not sure), but few people have one. But by disabling the ignition and cranking the starter for 15 seconds, you've subjected the battery to the most severe load it's ever likely to see. For testing, is this perfect? No. Thoroughly adequate? Yep! And with no added expense, too.

That's why I've been harping to duplicate the fault conditions and run the voltage drop test. Not sure if I've mentioned this before, but it's very important to begin testing with a FULLY charged battery.

And if that passes repeatedly, then you know the problem lies elsewhere. For example, the battery may not be getting a full charge from the alternator. But instead of zinging back and forth between various possibilities, I prefer to rule out (or confirm) some of the most likely scenarios. Furthermore, to help stay focused, I like to work a single scenario at a time.

Back to making sure a battery is fully charged, keep in mind nobody troubleshoots any system when all is working properly. When are you troubleshooting? When the system is acting up. And a very common side effect with an electrical system fault is a partially discharged battery. So you're already behind the 8 ball if you start troubleshooting under that condition.

Now I'll readily admit I've rushed through sometimes, and didn't bother fully recharging the battery first. But I've learned to be mindful of any limitations when shotgunning like that. Here's a purely hypothetical example. Let's say my imaginary '49 Mercury (5BA flathead V8, baby moon hubcaps, the works...) cranks very slowly on cold mornings. Even though I haven't diagnosed it yet, the actual root cause is going to be a glove box light staying on and partially running down the battery. Even though the engine is cranking slowly, the starter system itself is not at fault.

Let's make it interesting, and I start troubleshooting with a partially discharged battery. If run down far enough, that poor generator will struggle to recharge the battery. A voltmeter might only show 12 volts or so for a while, instead of the desired 13.5. Must be a bad generator, right? Time to place an order at ExpensiveElectricalComponents.com. This expensive mistake would have been avoided if the battery had been FULLY charged first.

In that same scenario with my imaginary '49 Merc (sorry, not for sale), I'd have encountered equally misleading results with a voltage drop test had I started with a partially discharged battery. Luckily, ExpensiveElectricalComponents.com combines shipping on multiple items, so I'd have that going for me.

Here's the good part. With a fully charged battery, the voltage drop test would have passed with flying colors. I'd have known within minutes (other than waiting for the battery to charge) that I should turn my attention elsewhere. And then once other troubleshooting led me to search for a battery drain, I'd have also found several hundred dollars (unmarked bills, random serial numbers) in the back of the glove box. I'd have used the money to support an animal therapy program for underprivileged children, all thanks to the voltage drop test.

Oh anyways, that's my verbose take on troubleshooting philosophy and the concept of compartmentalization. It helps avoid the squirrel-chasing tactics we are all prone to succumb to.

Back to that pesky fully charged battery we all need. How does one know when it's full? Some posts in this thread explained the voltages you should see, and that's all good stuff, but I'm terrible at remembering the certain values. (Edit) And if you don't properly bleed off any surface charge, a partially discharged battery may mistakenly appear full. That's why I like my charger's little green light. When it turns green, the battery has a good charge, suitable for testing. I know I could get more specific with a voltmeter or even a hydrometer for the ultimate in precision. But I'm lazy and that little green light is adequate for my needs. If shopping for a charger, I'd recommend a similar automatic model. Connect it and forget it.

 

Simply stated, I charge the battery fully over the course of whatever time until green light shows fully charge, and it is tested by disconnecting coil lead and cranking for 15 seconds, voltage should not drop below 10 volts. I believe that's exactly how Karl stated to initially start my testing.

If it then fails to maintain adequate voltage over that 15 seconds, I can then point at the battery.

Until then, off to the auto parts store to get my charger with a new found knowledge! Thanks everyone for your help! I will post up results hopefully Monday if weather permits.

 

Yep, you got it. Over the next few days, I'm thinking of editing the test a little bit, to help define when a battery is fully charged and ready for testing.

One slight caveat if the battery voltage does drop below 10 under the load of the starter. In rare cases, a starter can have an internal short that causes it to draw too much current under load. If so, a perfectly good battery may drop below 10v. The only way to confirm a fault like that is with a big inductive ammeter, the kind that clamps over the wire. Then you'd have to compare that reading to specs.

As a confirmed tool geek, yeah, I've got one. Actually two. But for what they cost ($100+), and due to the very low probability, you could safely shoot from the hip and replace the battery first if it was fully charged and dips below 10v with the starter engaged.

I think you had already replaced your battery recently? If so, then you get to flip a coin and decide whether the new battery is bad (rare, but happens) or if it's the starter. In that case, you could always have your battery professionally load tested, instead of using the starter as the load as we've been doing so far.

 

Indeed, the battery was replaced earlier this year with an overkill one since the willitlast brand doesn't make a 930cca one, I may be mistaken, but this one is a 1100cca big truck flavor.

........And yes it's a pain to pull and haul it around, so I'm gonna do the test first and we'll cross that bridge later.

I expect royalties from causing you to modify your wonderfully written article. I'm glad I was able to prove it wasn't idiot proof yet!

 

Are you okay with a post-dated third-party check written in foreign funds?

 

Always good to have good battery cables too. And get rid of those cable clamp terminals if you are using them.
Yeah these.....get rid of em.
I use to use them a lot but realized how terrible the contact is then the wire strand corrodes real bad on the inside...like green powder

 

As requested, the (end of the) test procedure has been edited to increase the level of idiot-proofedness.


https://www.ford-trucks.com/forums/1...w-starter.html

 

Bumpity bump time. Any recent progress?

 

And now for something completely different:

Seems to me his idle speed and mix may be in need of adjustment. If he has idle adjustment too far cracked open then fuel is dripping/siphoning/vaporising causing problems. Just a heads up. Also who knows exactly what the recurved distributor is up to....try some heavier springs. So adjust idle speed and mixture and after its warmed up go to work with a timing light paying attention to see how fast it's all in.

 

Merry Christmas everyone! My lack of a remote starter is keeping me from testing voltage drop while cranking, but my actual charger is showing a green light now, I'm ready to do some real testing. A last minute question for testing voltage drop, should I leave charger connected for testing voltage drop through positive and negative terminals to starter and ground? Or is it safe to disconnect it? Should I worry about any loss in voltage after disconnecting and skewing my readings? Hopefully tomorrow I'll be able to test cranking voltage tomorrow in which I'll know I have to disconnect to give me real life readings on what the engine is drawing.

An idea I always thought about the vaporizing of fuel in the bowls of the carb on a hot engine, and any idle mixture problems I hope to chase after electrical gremlins are solved. But I have heard of this being a problem as well as I am using cast iron intake manifold and have been advised to use aluminum edelbrock with heat crossover blocking. The vaporization I'd like to debunk by the fact that the engine can slow on first start, third, or last crank of the day, therefore, engine heat does not seem to play a big factor. Not ruling out idle either, but we were successful in setting it to close at 11.9 afr with min at 10.7 and max at 13.0

 

The wonderfully intelligent and helpful Scotty J did my dizzy recurve on a factory motorcraft unit. 14 degree btdc initial timing at idle, about 17" of vacuum, and 32 degree max total timing at 3000rpm no vacuum.

 

You could make your own remote starter with some zip cord and a switch. Alligator clips if you want to get all cork-sniffin' fancy.

 

 

Disconnect the charger. We're trying to duplicate real world conditions as much as possible, with one slight tweak. The use of the charger deliberately skews the results to simulate a perfectly functioning charging system on the truck. We're trying to eliminate as many variables as possible for troubleshooting. Thus, the ignition system is disabled for the voltage drop test. This eliminates any influence from too much timing advance. The fully charged battery eliminates any influence from an overnight battery drain or a weak charging system.

In a perfect world, you'd be able to duplicate the slow cranking while running these tests. Then you could finish the diagnosis and not necessarily worry about ignition timing, the charging system, carb settings, or who knows what else. Those could be contributing factors, but for the moment, stick to the slow cranking condition.

Duplicate the fault conditions as much as possible (heat, etc.) and run my long-winded test repeatedly until you are 110% sure the battery, cables, and the starter itself are not causing the slow crank. Once you're happy there, then investigate other possibilities, such as the battery not getting a full charge when driving, an overnight drain, timing issues, etc. One crisis at a time. Don't go chasing squirrels. Remember, the purpose of the battery charger is only to rule out certain scenarios for troubleshooting. It's not a fix by any means. It's only so you'd know which direction to pursue if the cranking speed is reliably good using a fully charged battery.

Don't worry about the surface charge present when you disconnect the charger . That's only an issue if trying to determine state of charge by measuring the voltage, which can give a false high reading. As soon as you demand several hundred amps to power the starter, that surface charge will be gone in a flash. It won't affect the test at all.




Your carb should have four mounting bolts at the base. Undo them, remove the carb, and set it on your workbench. Get a strong flashlight and peer inside the intake manifold. While doing that, think about how the carb itself should have virtually no effect on the ability of the battery, cables, and starter to spin the engine at a normal cranking speed. The carb will certainly affect the ability of the engine to start, but that's not what we're troubleshooting at the moment. Note I said virtually no effect. If the carb is flooding, all that extra fuel will wash oil from the cylinder walls and decrease compression. If all other factors are equal, cranking speed will actually increase due to less resistance. If my 351W floods, one huge clue is longer and faster cranking before the engine actually fires up.

I'm not trying to bust your chops, but want to isolate the primary fault as best as possible by reducing or eliminating possible influences. I'm reminded of the time my sister-in-law went into an absolute panic when her car wouldn't start after sitting for a few days. Turns out she normally drove it every day. The battery was old and tired, but the daily driving kept it adequately charged for starting the next day. Then she was gone on vacation for several days and the battery charge dropped. This had never happened before, as the car was normally driven every day, which helped hide the marginal battery condition. On top of that, the car was always kept in good mechanical condition (other than the geriatric battery), so the engine always started up right away. No extended cranking was ever needed, which also helped hide the battery's condition. She got back from her trip, and I got the panicked call from the airport parking lot. The perfectly good starter ran too slowly to start the engine, and the extended cranking further depleted the battery until it was nearly dead. It wasn't luck that helped me diagnose the bad battery. It came from following a diagnostic routine for the slow cranking fault that was present. Your truck? Who knows. But stick to a plan. One crisis at a time...