Seems strange, battery vs spark at the plug

[theHIGHLANDER]

So, I go out to take the A pickup to work the other day. The evening before I went through the carb and all was well in the fuel/delivery dept. I started it and it purred like she always does but stalled after 2-3 min. I re-started after checking the gas valve (it was open) and it ran ok. So the next morning I decide it's taking me to work but it won't start. I know I have fuel, I know the valve is open, it's cranking at the same speed it always does. I get out and do a cursory ignition check by pulling the coil wire and opening/closing the points, the wire lined up to a head bolt, I got spark. I hook it all back up and crank it over again, now checking spark at the plug with a screwdriver shorted to a head bolt. No spark, that is, until I release the starter and I see a single spark. Next, I short a plug to a head bolt, key on and raising/lowering the spark lever. I got spark. Now I'm scratching my head in a "WTF?" moment. Next I hook up a battery charger to the system and it fires right up. I shut it off, left it charging for 10 min or so as I load some parts and supplies I need at the shop, took the charger off, it lights up and runs fine. The generator is charging about 12-15 amps at full speed so I figure that's enough to keep it lit, but then it got me thinking about the same ills it has when running with the lights on. I flip em on and it's back, spittin and fartin all over itself at any speed over 40 MPH. Even below that it runs less than stellar. I checked battery voltage and it's at 6.37, but given enough time it drops to 6.0 something, even 5.99. The spark when checked is hot and blue, visible even in bright sunlight, but no spark at all when cranking if the battery is even a wee bit low? Something's amiss and I wouldn't mind some opinions. The cells all check out to about 2 volts each. The worst being 1.98. I can't get my head around the idea that .02 volts would bugger the ignition system, or that it won't run as it should with the lights on. All the basics are covered as in good grounds and cables, even dropped in some new spark plugs. Any ideas?

[Mitch//pa]

Originally Posted by theHIGHLANDER

So, I go out to take the A pickup to work the other day. The evening before I went through the carb and all was well in the fuel/delivery dept. I started it and it purred like she always does but stalled after 2-3 min. I re-started after checking the gas valve (it was open) and it ran ok. So the next morning I decide it's taking me to work but it won't start. I know I have fuel, I know the valve is open, it's cranking at the same speed it always does. I get out and do a cursory ignition check by pulling the coil wire and opening/closing the points, the wire lined up to a head bolt, I got spark. I hook it all back up and crank it over again, now checking spark at the plug with a screwdriver shorted to a head bolt. No spark, that is, until I release the starter and I see a single spark. Next, I short a plug to a head bolt, keuy on and raising/lowering the spark lever. I got spark. Now I'm scratching my head in a "WTF?" moment. Next I hook up a battery charger to the system and it fires right up. I shut it off, left it charging for 10 min or so as I load some parts and supplies I need at the shop, took the charger off, it lights up and runs fine. The generator is charging about 12-15 amps at full speed so I figure that's enough to keep it lit, but then it got me thinking about the same ills it has when running with the lights on. I flip em on and it's back, spittin and fartin all over itself at any speed over 40 MPH. Even below that it runs less than stellar. I checked battery voltage and it's at 6.37, but given enough time it drops to 6.0 something, even 5.99. The spark when checked is hot and blue, visible even in bright sunlight, but no spark at all when cranking if the battery is even a wee bit low? Something's amiss and I wouldn't mind some opinions. The cells all check out to about 2 volts each. The worst being 1.98. I can't get my head around the idea that .02 volts would bugger the ignition system, or that it won't run as it should with the lights on. All the basics are covered as in good grounds and cables, even dropped in some new spark plugs. Any ideas?

check the distributor lower plate wire for fraying and grounding.. flunctuations in the electrical circuit can make an effect on the dist wire if its only held on by a few strands.. sounds like you need a battery anyways and lower the charge rate..your statement of moving the spark lever leads me in this direction

[BILL WILLIAMSON]

Originally Posted by Mitch//pa

check the distributor lower plate wire for fraying and grounding.. flunctuations in the electrical circuit can make an effect on the dist wire if its only held on by a few strands.. sounds like you need a battery anyways and lower the charge rate..your statement of moving the spark lever leads me in this direction

X-2 on BOTH.
Bill W.

[SeaSlugs]

Originally Posted by Mitch//pa

check the distributor lower plate wire for fraying and grounding.. flunctuations in the electrical circuit can make an effect on the dist wire if its only held on by a few strands.. sounds like you need a battery anyways and lower the charge rate..your statement of moving the spark lever leads me in this direction

i thought this too when he said moving the lever created spark again.

[Russell in Tulsa]

Unless I didn't comprehend all that is needed to know, doesn't the battery have enough ass to start the car after he repairs the lower wire situation? Or is it considered marginal?

[Bob C]

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12-15 amps is to high a charge rate. I would also load test the battery,
may also be a problem there the way the voltage is dropping.

Bob

[Mike V. Florida]

The moving of the lever up and down is opening and closing the points as it should.

The fact that it will not spark with the starter running, tells me you have a bad battery.

The part about 12 amps when running tells me why you have a bad battery.

[jmeckel]

Also check and clean all of the ground paths, and the supply side to the coil. Actually just clean all your electrical connections. A dirty connection or loose wire can have these type of issues.

[Bobant]

Have the same problem. That is car runs fine , but turn the lights on and after 5 minutes all goes bad. Turn the lights off and car runs great. I was told it was the battery , although relatively new, but i did not buy a new one yet. One additional hint, I keep the car on a trickle charger. Last night I went to start it and the fuse was blown on the starter. Changed the fuse and off and running. Fuse blown just from trickle charger- leads to bad battery I think. Didn't mean to steal your post, but problem seems pretty close to yours. I have noting else to check as I have ckecked every other thing I can- I took all the bulbs out and turn lights on and no problem so eliminates shorts.

[marc hildebrant]

You have a bad battery...

One result of a battery going bad, is that the internal resistance of the battery goes high. What this means is that a small load say from the ignition system would still have about 6 volts applied to it. But, when a heavy load (starter) is applied, the voltage drop due to the high internal resistance makes the ignition voltage drop way down.

Marc

[theHIGHLANDER]

It's been sitting since Friday. I'll throw a volt meter on it and see if it's dropped any since the slow charge I gave it. Even when the battery was new, meaning the day of purchase, the generator would not charge at all with the lights on. After a couple starts it would charge between 5 and 10, no lights on, about 8-10 discharge with the lights (sealed beams). I moved the 3rd brush and got the charge rate up to about 12, then with the lights on about 0-2 amps. I guess I'll take the battery back and see what's up if it checks out below 6 volts tonight. I can't see driving for nearly an hour at night with the battery discharging all that time with the lights on. I think I'd be dead in the water before I got home. I like using the truck for evening events, races, cruise nights, etc. I'll report back what I find, and thanks for the insights so far.

[Tom Wesenberg]

I would use stock lights. It seems your sealed beams may be using more amps than the Model A generator was designed to handle.

[theHIGHLANDER]

So, I've been up to my butt cheeks in alligators trying to finish a Packard. On Wednesday I became a year older so I drove the A pickup to work. It had been sitting for more than a week and I never did get (make) the time to throw a meter on the battery. It's prior outing I had given the battery a 3 hr trickle charge and added maybe 3-4 oz of water to each cell. I was pleasantly surprised to find that it no longer had the erratic performance with the lights on. It's charging about 12-15 amps w/out lights at 45-50 MPH (it likes that speed, go figure) and 0-2 amps with the low beams, 0 with the highs. I guess the battery (now going on 3 yrs old) just wanted a little attention. I've since finsihed the Packard (9pm last night) and I hope to pile some miles on it and see if that's all it was. I do agree though, the sealed beams must be more needy than the regular bulb lights. I could move the 3rd brush back a bit with a swap. Maybe I'll find time to switch em soon, and that's a big maybe. Now I need to get one ready for the ACD festival in Auburn, IN on Labor Day weekend. That's next week isn't it? Hell I dunno...

[johnbuckley]

I agree with all the above posts. Another thing to consider is I had a rogue worn-out starter that turned the engine OK but left hardly any current for the ignition circuit when churning. It would start fine on the handle and of course HT lead gave an excellent spark when using a screwdriver at the points. Also had a A that faltered when I switched the turn signals on - this was wired with the circuit to the coil and took all the juice.

[Keith True]

I just went through the same thing with a pickup.I really had a strong suspicion of some kind of resistance in the repro ignition switch,and I told the owner to drop the dash to take it out.I told him to go over every connection under there too,not just look and shake,but remove and clean.He said one terminal on the ammeter was black.He swung one wire on the ammeter to the other post to make it direct,it still acted up.He took both off and tied them together and it starts fine.It also runs better,we think the ammeter must have been bleeding a little juice off all the time.

[Mike V. Florida]

Originally Posted by theHIGHLANDER

It's charging about 12-15 amps w/out lights at 45-50 MPH (it likes that speed, go figure) and 0-2 amps with the low beams, 0 with the highs.

WAY too high.

[theHIGHLANDER]

I get the battery charge thing, I get 3rd brush adjustments, amp draw, good connections, and all the rest. If I set the generator to something lower I get a 5 amp discharge with the lights on. No, the lights are not suffering a bad ground, loose connections, demons or spider infestation. "Ok Highlander, then how do you expect the battery to live if you charge it 15 amps at all times?" I don't. I expect it to occasionally drop back as the voltage comes up after a start, or after the lights have been on for a long time, or any other load that may be encountered. Please note that I like discussions here for the most part and feel that those with similar issues or foibles may get something from it, however if what's being replied isn't comprehended completely one may think some asshat owns an old A pickup and doesn't know WTF he's doing. SO, to clarify, and to HELP OTHERS, one who indeed said he had the same gig, IT DOESN"T CHARGE 15 AMPS AT ALL TIMES THE LIGHTS ARE OFF. I get 12-15, maybe it even drops back more and I simply don't see it. Surely none of us spend more time looking at the instrument board than the road. Also, while not initially shared in this topic but mentioned in another, I flip my lights on for 5 or so miles at a time now and then in an effort to keep the battery from getting cooked by the generator. I do this mainly at high speeds. Is it possible that it works the battery like a pack mule when I do? I did say it likes 45-50 MPH and I'd bet a spark plug that the ignition draw on the simple electrics of our beloved As is greater at higher RPM, and maybe that's why the cutout doesn't, well, cut out.

I sincerely thank those who read thoroughly and provide constructive input and opinion, but it gets old reading replies from some who think the basics were not covered because they didn't read it all. Is it the position of those most in-the-know that 2 amps additional output will cook a battery? 10 would be the sweet spot, correct? Something lower at low speeds and longer drive times could be seen too, right? This assumes that EVERYTHING ELSE is tip-top. It is. I live in the country. I can't simply walk home or hope someone happens to pass by that gives a fat rat's hiney about us old car folk. Therefore I like my old stuff reliable and safe. If this comes off as drama to anyone, that's on you not me. If I am missing something I wouldn't mind some positive input and opinion. Thanks again y'all, and happy motoring...

[Tom Wesenberg]

The cutout only cuts out when the generator puts out less than battery voltage. In other words it's a simple OFF-ON switch that should always be closed when the engine is running and should be open when the engine is stopped.

I only use generators that have an EVR so I don't have to worry about overcharging or undercharging the battery.

The third brush should be set so the ammeter shows 2 or 3 amps for average driving. If you do a lot of short drives with engine stops and starts then the ammeter needs to be set higher.

When you drive at night with the lights on you should readjust the third brush to run the lights and still put an amp or two charge into the battery at fast idle.

The coil actually draws less amps the faster the engine runs, but normal draw is about 1 to 1 1/2 amps with the engine running. With the engine stopped and points closed with the key on the amp draw should be about 4 amps.

[theHIGHLANDER]

Makes good sense Tom, thanks. I actually do a lot of short drives. Sunday breakfast is only 12 miles round trip, my shop is 4.9 miles from "key on" to "key off". I'd expect to smell acid and see damage if I drove a 75-100 mile tour at a time. I'm also set there, about 0-2 amps with the lights on. At slow speeds/idle I get a discharge with the lights on, but I expect that. How kool would it be to adjust the 3rd brush "on-the-fly"? Ok, ok, maybe not so kool. Just being silly...

[Kurt in NJ]

If you have read your owner's instruction book you would know that there is supposed to be a discharge with the lights on

also in the service bulletins there are instructions about setting the charge rate (page 504,winter electric troubles)----battery can be used as a guide in determining correct charg rate

There is no set charge rate that is good for every car/owner --I have had a 14 amp rate for the last 15 years, I never charge the battery other than driving, I have long battery life, 16 years from the last battery (Optima), the battery in my car now is 15 years old, but it spent it's first 10 years as a 12V battery---then I cut it in 1/2 to make it 6V

When checking the electrolyte level only fill to full if fully charged, only to cover the plates if discharged ---the level rises as battery becomes charged, filling when discharged causes overflow when charged

When I had 50cp regular bulbs I had to really crank the generator high (18 amps) to make them bright --this is in the kill the generator zone, I only ran with the cover band off to give it cooling air ---then I put in quartz halogen bulbs, I reduced the rate for them

There is no amp rate number that will work for all use , without knowing your use and monitoring your battery any amp number given as a charge rate is just a starting point

My 14 amp rate works for me with about 50% headlight on time, if I do a long daylight drive I turn on the lights for a portion of the trip

Everybody should read the winter electric trouble article on page 504, it applys to our modern limited use of of the A and has very good advise on caring for the electric system

[marc hildebrant]

Without voltage regulation on the generator, you really have to take an active role in setting the third brush for the different driving conditions.

When I had my 1933 Chevrolet with a third brush, I installed a variable resistor in the dash in series with the third brush output. I then set the third brush at the max setting and adjusted the output from the car as I drove around.

At that time, I didn't care about adding extra holes in the dashboard or keeping the car original.

By the way, the Chevrolet design for the generator had the third brush adjustment coming out of the end of the generator, so that it could be adjusted without removing anything.

Marc

[Tom Wesenberg]

For a simple variable output control the way Marc did it with a rheostat is the easiest, but I have seen a couple generators where someone rigged a lawn mower throttle cable to the adjustable brush to set the amperage while driving.

I like the electronic voltage regulator the best because the lights are safe from too much voltage and the battery is always getting the correct charge.