SA electrical problems partially solved

For those of you that have followed this thread, here are today"s findings:


The distributor is 180 degrees out....so we moved the wires accordingly to put it back in time. The new coil I had bought wasn"t making a lot of spark, so my pal mounted an old, but good, 12 volt coil and the tractor fired right up!

For about 5 minutes and then quit.

Hmmm!

That coil was dead as a mackerel. In fact, when it died today, it acted just as it did when this problem started......run a minute or so and die.

I had a thought.....what if the alternator was charging wide open.....dumping totally unregulated voltage into the system.....could/would that kill a coil?

Obviously, I had to get another coil before the engine would start again and so, I did. I bought a new 12 volt UNballasted coil, added a ballast and fired her up. I checked the VOLTmeter and it was off the scale...buried to the right!

I unhooked the alternator and let the engine run off the battery and then stuck the fluke meter to the alternator....19.4 volts! I never even tried an amp reading.

So.....maybe I am wrong, but I think the alternator fried my first coil, fried the good old one we mounted this morning and would have fried the new one had I left the alternator hooked up.

Oh...have I ever noticed anything with the battery before....No. I think this alternator issue just started.....as in when the tractor first quit a few days ago and I have been busy trying to fix it ever since.

Whatever the reasons, the tractor runs fine now. Hot coil and plug wires put where they needed to be.

So you got it running. Great! Glad we're past that. (That's two cases of being 180* out in two days, so nobody should be too awful embarrassed about having that happen.)

I don't know alternators from squat, but high 13s, low 14s is what I'd think it ought to be putting out for voltage, so that may well be the source of your problem.

Im gonna sit back and see what the guys who know about such things some up with.

I DO NOT recommend you unhook an alternator when running, I hope it isnt damaged !!!!!!!!!!

As far as the coil the LABELS can be confusing:

A full true 12 volt coil (NO ballast required) may be labeled "12 volts" or "12 volts NOT for use with ballast" soem call tehm internally ballasted

A coil labeled "12 volts for use with external ballast" is in reality a 6 volt coil and needs the ballast just as it says

If the new coil you bought is a full true 12 volt coil YOU DONT USE AN EXTERNAL BALLAST

I figured it had to be an out of register out of time (as so many of us posted) situation if the coil fired but there were no plugs firing

Thanks for the feedback

Got to run I will check back later

John T

John,

The coil says 12 volt for use with an external ballast...and that"s what it got. The new internally ballasted version put out a very, very weak spark. This new one...as well as the old/but good one we used this morning would/will make Frankenstein laboratory sparks!

I don"t give a darn if that alternator is toast.....I am afraid it is the culprit and would never trust it again anyway. One wire GM alternators are easy to get.

Scotty, as far as the time being 180 off....well, whomever had the machine before me has evidently had the distributor off and put it back on that way.....I have never touched it. Had I paid any attention before removing the old wires.....that would have been a tip-off. I also don"t know if 19+ volts can kill a coil or not.....but I"m not taking any chances!

I agree, Mark, the timing sounds like a problem you inherited, and you get points for sticking with it to track it down. It's not the kind of thing you look for on a tractor that was running.

And I'm with you on the alternator. Maybe somebody will chime in and say that voltage is normal and suggest some other problem, but I wouldn't trust it. It well could be the source of the problem with the burned points, especially if it's toasting coils. on that score, it probablly wouldn't hurt to have another condenser on hand before you get through.

What is the voltage at the battery terminals? Is it bubbling?

Great, I just wanted to confirm what coil you had..... If an alternator is coupled up to the battery/load and the battery voltage is rising to 19 volts thats wayyyyyyy toooooooo highhhhh, its internal voltage regulator must be bad (assuming all is wired correct especially the voltage sense circuit) and the battery can overcharge n boil over acid n get ruined eventaually plus YES the points will burn up faster and the coil run too hot

Sounds like your getting there, she sure runs better if when the points break open the rotor tip is where its supposed to be i.e. lined up with a cap pickup leading to wire and plug located in a cylinder thats nearing TDC on its compression power stroke woooooooo hooooooooooo

CONGRATULATIONS

John T

Great. Now the Alt issue and it will be finished. JimN

had a auto mechanic's teacher in high school that was as good a tractor mechanic as they come,he converted a many a tractor to 12 volts,he warned us about disconnecting the battery while engine was running to see if alt. was charging enuogh to keep engine running,he said that if circuit was disconnected that the regulator sometimes wouldn't control the voltage and it would spike burning up electrical parts,well hard headed me kept doing it any from time to time until i blistered the alt. and coil on my sa ,had to replace them instead of cultivating that morning live and learn.

(quoted from post at 22:55:21 11/04/09) had a auto mechanic's teacher in high school that was as good a tractor mechanic as they come,he converted a many a tractor to 12 volts,he warned us about disconnecting the battery while engine was running to see if alt. was charging enuogh to keep engine running,he said that if circuit was disconnected that the regulator sometimes wouldn't control the voltage and it would spike burning up electrical parts,well hard headed me kept doing it any from time to time until i blistered the alt. and coil on my sa ,had to replace them instead of cultivating that morning live and learn.

Click to expand...

Yep, alternators/regulators vary and under the right conditions 100 volts + is available. He said he measured alt out put with alt disconnected from battery. That is what I would call a meaningless measurement. Much better to measure highest it raises battery voltage to after a nice long run. If you have all the correct load resistors & test eqmt, it can be done without the long run time, but for most situations just determine where battery settles out after hour or two of operation, voltage wise.
Here is a Delco 10Dn, near full field ........lots of voltage, lots of amps (not a spike, but steady output).

Many auto parts stores offer free alternator testing. You might want to take advantage of that service.

Unfortunately, we will never know if the alternator was the culprit, or if disconnecting the alternator and running it caused it to fry.

Friends, one and all,

Thanks to everybody who chimed in, all great information and help, my hat is off to all of you.

I am almost 52 years old and continue to learn something new, everyday. It"s obvious I am not a full time mechanic or troubleshooter....and I"m glad this old iron runs trouble-free most of the time. It wouldn"t be much fun if it was work on three days to use it 2 hours, everytime you needed the machine.

I don"t use this old Super A much....just cultivate the garden during the summer and beyond that, it pretty much sits. Hugh MacKay sent me plans for a 3 point conversion and I just might try to cobble that together this winter.

Thanks again for all the help.

The discussion even "sparked" a lively debate, can't beat that!! Jim

The real beauty of these old Farmalls is that once you get all of the bugs worked out, they're good to go for another 20 to 30 years.