Please help, my tractor won't start!

[Diamondpilot]

Sound Guy can talk you through these old tractors but since its a 12 volt system just junk the Genny and Voltage Regulator and spend $60 and get a 1 wire 10 or 12 SI GM alternator and install. Any auto parts store will have them. It will put out about 65 amps, 5 times what you need on a tractor. Just one wire to hook up to the positive post of the battery and you will now have a moderns system that is trouble free for the most part. 1000's of old machines have had this done.


Chris

 

[Soundguy]

you can make a genny spin like a motor by applying power to it's armature and ground, and then biasing it's field depending on field circuit type. B circuit gennies like power to the field.. a circuit gennies like ground on the field... I'd suspect that unit is a circuit... got to slip the belt off.. if genny spins on a motor test.. they -usually- will charge. A full field test is during operation, and you essentially power or ground the field, depending on field circuit type.. thus making the unit deliver full charge.. this will tell you if the reg is working.. IE.. no charge normally.. but full field makes a charge.. then field ckt in reg is bad. can also bypass the cutout in the reg and jumper bat to arm during the fld ckt test.. this will tell you if the cutout is open etc...

5 minute test.. tells you if your genny will charge and if the reg is good.

a ckt regs have a bias resistor from grnd to fld on the underside of the can.. b ckt regs have a bias resistor from arm to fld on the underside of the can... may be more resistors present as well. If it has never charged.. might be wrong vreg..

soundguy

 

[Harley T]

My tractor is FIXED!!!!

Thanks for the help, soundguy. However, like diamondpilot suggested, someone had ALREADY swapped out the generator and vreg for a GM alternator. Mine turned out to be off and old Chevy. LOL

Last night, I hooked up my tester to the tractor. The battery % started around 85, but slowly dripped lower. The alternator % was -0-. Today, I took the alternator to the auto parts store and tested it on their machine. They told me it was pretty low, the problem was probably in the voltage regulator. Had to scrape a lotta grime off of it to get the part number, but eventually found it. $35 bux for a brand new one. Came home, put it on, plugged it in, and the battery % quickly went from 74% to 100%. The alternator % is 160.

Problem solved. Thanks again to everyone for your help. I hope I can return the favor sometime.

Harley

 

[Soundguy]

was this an old external reg model.. perhaps like a 10dn or similar?

soundguy

 

[Harley T]

<<was this an old external reg model.. perhaps like a 10dn or similar?>>

Don't know if you're talking about the tractor or the alternator. The tractor is supposed to have a generator and separate external vreg. The alternator I took off had the vreg in it.

The test at the auto parts store said the alternator was low, the problem is probably the vreg inside it.

Turns out, the battery is bad, too. Won't hold a charge. After I get it running, the battery % rips up to 100. However, after a couple of hours, it's back to only 60% or so. Gonna replace that today.

Harley

 

[Soundguy]

A 10dn is a delco alternator... has an external regulator.

soundguy

 

[Harley T]

It was a delco alternator, but the vreg was inside.

 

[Soundguy]

sounds like a 10si then.

soundguy

 

[Goodmechanic]

There should not be a spark that jumps the points when they are opened. You may sometimes get a little contact flash when they open, but never a spark. A spark across the open points is a contiunation of current flow and a good indicator for a bad condensor. Replacing the spark plugs was a good idea as new plugs would allow an already poorly operating ignition system to fire slightly better. This may sound silly, but I've seen it before, make sure your fuel petcock is open fully and not plugged. A running engine will drain a carburetor if the fuel flow is restricted and give the same symtoms. Letting the tractor sit to go get spark plugs would give the carb time to refill. Just a couple of things to check.

 

[Soundguy]

bad condensor specifically as an open one. as opposed to a shorted one in which there would be no spart at the points or plugs

soundguy